| Folder 34/1 | Lafleur, Henry A.. — 1910; (to Thayer). |
| Folder 34/1 | Lamb, D. S.. — 1920 |
| Folder 34/1 | Lamb, Robert S.. — 1927-1930 |
| Folder 34/2 | Lambert, Alexander. — 1919 |
| Folder 34/2 | Lambert, Samuel W.. — 1930, 1931; encl: reprint "Phineas Fletcher" by SWL Am Med Hist, 1931. |
| Folder 34/3 | Lambert, Samuel W.. — 1931 |
| Folder 34/4 | Lamont, Austin. — 1928-1932 |
| Folder 34/4 | Lamson, Paul D.. — 1929, 1931 |
| Folder 34/4 | Lange, Linda B.. — 1923 |
| Folder 34/5 | Lanier, Henry W.. — 1919 |
| Folder 34/5 | Lanman, Charles R.. — 1910, 1929 |
| Folder 34/6-7 | Lape, Esther E.. — 1925-1932; encl: booklet re American Foundation Inc.. |
| Folder 34/8 | Laporte, Ewing. — 1921 |
| Folder 34/8 | Larkey, Sanford V.. — 1930 |
| Folder 34/8 | Laubach, Charles A.. — 1919 |
| Folder 34/8 | Laughlin, J. Lawrence. — 1931 |
| Folder 34/9 | Lawler, Elsie M.. — 1919 |
| Folder 34/9 | Lawrence, Cynthia. — 1930, 1931 |
| Folder 34/9 | Lawrence, Joseph S.. — 1921 |
| Folder 34/9 | Lawrence, Rev. William. — 1919, 1934 |
| Folder 34/10 | Layman, David T.. — 1923 |
| Folder 34/10 | Leach, Charles N.. — 1922 |
| Folder 34/11 | Leake, Chauncey D.. — 1929-1934 |
| Folder 34/12-23 | Learned, Dwight W.. — 1869-1933 |
| Folder 35/1 | Leathers, W. S.. — 1920-1926 |
| Folder 35/1 | Lee, Frederic S.. — 1920 |
| Folder 35/1 | Lee, Ivy L.. — 1925 |
| Folder 35/2 | Legge, Thomas M.. — 1919-1930 |
| Folder 35/3 | Letulle, Maurice. — 1916 |
| Folder 35/3 | Leven, M. le Dr.. — 1933 |
| Folder 35/3 | Levene, P. A.. — 1933 |
| Folder 35/4 | Levin, M. B.. — 1918-1934 |
| Folder 35/4 | Levitt, Albert. — 1923, 1926 |
| Folder 35/5 | Levy, Robert L.. — 1930 |
| Folder 35/5 | Lewis, Burdette G.. — 1925 |
| Folder 35/5 | Lewis, Dean. — 1932 |
| Folder 35/5 | Lewis, Mary P.. — 1930 |
| Folder 35/5 | Lewis, Paul A.. — 1919-1921 |
| Folder 35/5 | Lewis, W. A.. — 1930 |
| Folder 35/6 | Libby, Walter. — 1922 |
| Folder 35/7-15 | Libman, Emanuel. — 1900-1934 |
| Folder 35/16 | Licht, Sidney H.. — 1929 |
| Folder 35/17 | Light, Richard U.. — 1931 |
| Folder 35/17 | Lihlman, Frederick N.. — 1930 |
| Folder 35/17 | Lilienthal, Edna (Mrs. Joseph L. Lilienthal). — 1933 |
| Folder 35/17 | Lindeman, W. H.. — 1931 |
| Folder 35/17 | Linden, Harry. — 1929 |
| Folder 35/18 | Lindsly, Cora. — 1915 |
| Folder 35/18 | Linninger, George F.. — 1902 |
| Folder 35/18 | Lipschutz, Benjamin. — 1922 |
| Folder 35/18 | Lister, Lord. — 1898; (envelope only). |
| Folder 35/18 | Littell, Robert. — 1923 |
| Folder 35/18 | Liveing, Mrs. Susan. — 1929 |
| Folder 35/19 | Lockard, Carroll. — 1933, 1934 |
| Folder 35/19 | Loeb, H. W.. — 1923 |
| Folder 35/19 | Loeb, Leo. — 1933 |
| Folder 35/20 | Loewenhart, Arthur S.. — 1920, 1921 |
| Folder 35/20 | Logan, Edward L.. — 1933 |
| Folder 35/20 | Login, Mr. ?. — 1929; encl: poem by Mitchell SW "Death of pain" re anesthesia celebration, 1896 (50th). |
| Folder 35/20 | Lombard, Warren P.. — 1919 |
| Folder 35/20 | Lomonossoff, Raissa. — 1930 |
| Folder 35/21-24 | Longcope, Warfield T.. — 1903-1934 |
| Folder 35/25 | Loomis, Alfred L.. — 1884 |
| Folder 35/25 | Lord, J. B.. — 1930 |
| Folder 35/25 | Loree, L. F.. — 1930 |
| Folder 35/26 | Loveland, E. R.. — 1931 |
| Folder 35/26 | Lowell, A. Lawrence. — 1910; (to Thayer). |
| Folder 35/26 | Lublin, Raymond. — 1929 |
| Folder 35/27 | Luce, Henry W.. — 1921; encl: booklet re Peking University. |
| Folder 36/1 | Ludlum, Helenie (Mrs. S. de Witt Ludlum). — 1930 |
| Folder 36/1 | Ludlum, Seymour D.. — 1898 |
| Folder 36/1 | Ludwig, Carl. — 1885 |
| Folder 36/2 | Lusk, Graham. — 1923-1930 |
| Folder 36/3 | Luttinger, Paul. — 1927 |
| Folder 36/3 | Lyle, Annie G.. — 1930, 1931; encl: Prospectus Pacific Foundation Stanford University. |
| Folder 36/4 | Lynn, Frank S.. — 1922 |
| Folder 36/4 | Lyster, Brig. Gen. Theodore C.. — 1919-1930 |
| Folder 36/5 | MacAlister, Sir John. — 1919-1920 |
| Folder 36/6 | MacCallum, G. A.. — 1927 |
| Folder 36/6 | MacCallum, William G.. — 1905-1923 |
| Folder 36/7-8 | MacCallum, William G.. — 1923-1934 |
| Folder 36/9 | MacCarty, William C.. — 1923 |
| Folder 36/10 | MacConnell, John W.. — 1931 |
| Folder 36/10 | MacCracken, Henry M.. — 1915 |
| Folder 36/10 | Macfarlane, Andrew. — 1919 |
| Folder 36/10 | MacGregor, John A.. — 1919 |
| Folder 36/11 | Macht, David I.. — 1930-1931 |
| Folder 36/12 | Mackall, Leonard L.. — 1930-1934 |
| Folder 36/12 | Mackay, Clarence H.. — 1930 |
| Folder 36/13 | Mackenzie, A. Stanley. — 1921 |
| Folder 36/13 | MacKenzie, Elizabeth J.. — 1923 |
| Folder 36/13 | MacLean, George E.. — 1930 |
| Folder 36/13 | MacNider, William de B.. — 1930 |
| Folder 36/14 | Macomber, Mabel E.. — 1926 |
| Folder 36/15 | Madsen, Thorvald. — 1910-1931 |
| Folder 36/16 | Magoffin, R. V. D.. — 1920 |
| Folder 36/16 | Major, Ralph H.. — 1929 |
| Folder 36/17-27 | Mall, Franklin P.. — 1885-1911; encl: TMs "A plea for an Institute of Human Embryology" by FPM. |
| Folder 37/1 | Mallet, Bernard. — 1927; encl: Program World Population Conf Geneva. |
| Folder 37/2 | Malloch, Archibald. — 1910-1934 |
| Folder 37/3 | Mallory, Frank B.. — 1930 |
| Folder 37/4 | Malone, Dumas. — 1932 |
| Folder 37/5 | Malone, Inez (Mrs. Kemp Malone). — 1933 |
| Folder 37/5 | Manheimer, Wallace A.. — 1920 |
| Folder 37/5 | Manwaring, W. H.. — 1920 |
| Folder 37/6-7 | Marburg, Theodore. — 1910-1933 |
| Folder 37/8 | Marburg, William A.. — 1910; (to Thayer). |
| Folder 37/8 | Marchand, Felix. — 1909-1927 |
| Folder 37/8 | Marchand, Martha (Mrs. [Frau] Felix Marchand). — 1928 |
| Folder 37/9 | Markle, John. — 1925 |
| Folder 37/9 | Marquardt, Martha. — 1921 |
| Folder 37/9 | Marquette, Bleecker. — 1930 |
| Folder 37/10 | Marshall, C. J.. — 1933 |
| Folder 37/11 | Marshall, Carrington T.. — 1930; encl: booklet "Judicial statistics Ohio". |
| Folder 37/12 | Marshall, Don. — 1931 |
| Folder 37/12 | Marshall, Harry T.. — 1920 |
| Folder 37/12 | Marshall, John F.. — 1928 |
| Folder 37/13 | Marshall, L. C.. — 1933 |
| Folder 37/13 | Martin, C. B.. — 1934 |
| Folder 37/13 | Martin, C. J.. — 1921 |
| Folder 37/14 | Martin, Franklin H.. — 1919, 1932 |
| Folder 37/15 | Martin, Sarah F.. — 1920 |
| Folder 37/15 | Martland, Harrison S.. — 1932 |
| Folder 37/16 | Marvel, Philip. — 1927 |
| Folder 37/17 | Mason, Max. — 1930-1933 |
| Folder 37/17 | Matas, Rudolph. — 1910, 1930 |
| Folder 37/18 | Mather, Winifred H. (Mrs. Rufus E. Mather). — 1932-1933 |
| Folder 37/19 | Mawer, Allen. — 1931 |
| Folder 37/19 | Mawson, W.. — 1919 |
| Folder 37/19 | Maxcy, Kenneth. — n.d. |
| Folder 37/20-22 | Mayer, Joseph. — 1929-1932; encl: 3 reprints by JM including "American influence on development of science". |
| Folder 37/23 | Mayo, Charles H.. — 1919 |
| Folder 37/23 | Mayo, William J.. — 1910-1920 |
| Folder 37/24 | McAneny, Mrs. George. — 1930 |
| Folder 37/24 | McCabe, Gillie (Mrs. Gordon McCabe). — 1920 |
| Folder 37/24 | McCabe, W. Gordon. — 1920 |
| Folder 37/25 | McClung, C. E.. — 1920 |
| Folder 37/25 | McClure, James G. K.. — 1871-1930 |
| Folder 37/25 | McClure, James G. K.. — 1932 |
| Folder 37/25 | McClure, Mrs. James G. K.. — 1931 |
| Folder 37/25 | McClure, Roy D.. — 1925 |
| Folder 37/26 | McCollum, Elmer V.. — 1919-1920 |
| Folder 37/27 | McCook, I.A., (Mrs. J. J. McCook). — n.d. |
| Folder 37/27 | McCoy, G. W.. — 1927-1930 |
| Folder 37/28 | McCoy, G. W.. — 1930-1931 |
| Folder 37/29 | McCracken, Sue Z.. — 1920 |
| Folder 37/29 | McCrae, John. — 1910; (to Thayer). |
| Folder 37/29 | McCrae, Thomas. — 1930, 1933 |
| Folder 37/29 | McCue, John F.. — 1919 |
| Folder 37/29 | McCutcheon, S. S.. — 1871 |
| Folder 37/30 | McElroy, Robert. — 1928 |
| Folder 37/30 | McEwan, J. S.. — 1920 |
| Folder 37/30 | McGlannan, Alexius. — 1930 |
| Folder 37/30 | McGuire, Edward. — 1910; (to Thayer). |
| Folder 37/30 | McHatton, Elisa H.. — 1934 |
| Folder 37/31 | McKibben, William K.. — 1924 |
| Folder 37/31 | McKinley, Earl B.. — 1932; encl: reprint "Studies on leprosy" by EBMcK in JAMA 1932. |
| Folder 37/32 | McLane, Kate M.. — 1910 |
| Folder 37/32 | McLaughlin, A. J.. — 1923 |
| Folder 37/32 | McLaughlin, Katharine. — 1925, 1932 |
| Folder 37/32 | McLeod, John K.. — 1930 |
| Folder 37/32 | McMillan, W. C.. — n.d. |
| Folder 37/32 | McMurtry, L. S.. — 1922 |
| Folder 38/1-2 | Mead Kate C.. — 1930-1933 |
| Folder 38/3 | Mead, Elsie C. (Mrs. Robert Mead). — 1929, 1930 |
| Folder 38/3 | Meleney, Frank L.. — 1927 |
| Folder 38/4 | Meloney, Marie M. (Mrs. William B. Meloney). — 1930 |
| Folder 38/4 | Meltzer, Samuel J.. — 1901-1920 |
| Folder 38/5 | Mendelson, L. B.. — 1884 |
| Folder 38/5 | Menninger, C. F.. — 1902 |
| Folder 38/6 | Mercur, William H.. — 1920 |
| Folder 38/7-8 | Merriam, John C.. — 1923-1933 |
| Folder 38/9 | Merrill, Theodore C.. — 1924 |
| Folder 38/9 | Merritt, Ralph P.. — 1920 |
| Folder 38/10 | Metcalf, George D.. — 1871 |
| Folder 38/11 | Metcalf, Maynard M.. — 1930 |
| Folder 38/11 | Metz, Herman A.. — 1921 |
| Folder 38/12 | Meyer, Adolf. — 1920, 1921 |
| Folder 38/12 | Meyer, Mary, (Mrs. Adolf Meyer). — 1931 |
| Folder 38/13 | Meyer, Prof. Dr. Adolf. — 1928-1929 |
| Folder 38/13 | Meyer, A. W.. — 1924 |
| Folder 38/14 | Meyer, Arthur L.. — 1930 |
| Folder 38/14 | Meyer, Elizabeth (Mrs. Arthur L., nee E. Thiess). — 1931 |
| Folder 38/15 | Meyer, Ernst C.. — 1921 |
| Folder 38/16 | Meyer, Agnes (Mrs. Eugene Meyer). — 1930 |
| Folder 38/16 | Meyer, Willy. — 1925 |
| Folder 38/17 | Michaelis, Lorenz. — 1930 |
| Folder 38/17 | Michelson, A. A.. — 1930 |
| Folder 38/18 | Mieli, Aldo. — 1928 |
| Folder 38/19 | Milbank, Albert G.. — 1929-1934 |
| Folder 38/20 | Millard, Alfred M.. — 1865-1866 |
| Folder 38/20 | Miller, C. O.. — 1895 |
| Folder 38/21-25 | Miller, George D.. — 1870-1929 |
| Folder 38/26 | Miller, Sydney R.. — 1921-1931; encl: program American College Physicians meeting Baltimore. |
| Folder 38/27 | Miller, William S.. — 1933, 1934 |
| Folder 38/27 | Millikan, Robert A.. — 1930 |
| Folder 38/28 | Mills, H. W.. — 1926 |
| Folder 38/28 | Minor, J.L.. — 1933 |
| Folder 38/28 | Minra, K.. — 1923 |
| Folder 38/29 | Mitchell, Broadus. — 1930, 1933 |
| Folder 38/29 | Mitchell, S. Weir. — 1910; (to Thayer). |
| Folder 38/30 | Mittell, Sherman F.. — 1932 |
| Folder 38/30 | Miyairi, K.. — 1923; encl: TMs re "Development of medical science in Japan" by KM. |
| Folder 38/30 | Miyajima, M.. — 1930 |
| Folder 38/31 | Moffitt, J. K.. — 1919 |
| Folder 38/31 | Monroe, Anna (Mrs. William S. Monroe). — 1933 |
| Folder 38/31 | Montague, Amy. — 1924 |
| Folder 38/31 | Montgomery, Douglass W.. — 1930 |
| Folder 38/31 | Montgomery, E. E.. — 1920 |
| Folder 38/32 | Moon, V. H.. — 1933 |
| Folder 38/32 | Moore, Ernest C.. — 1930 |
| Folder 38/32 | Moore, E. H.. — 1919 |
| Folder 38/33 | Moore, Harry H.. — 1926-1933 |
| Folder 38/34 | Moore, John B.. — 1930 |
| Folder 38/34 | Moore, Veranus A.. — 1925 |
| Folder 38/34 | Moorman, L. J.. — 1934 |
| Folder 38/35 | Morgan, A. C.. — 1919 |
| Folder 38/35 | Morgan, John H.. — 1902 |
| Folder 38/35 | Morgan, John T.. — 1898 |
| Folder 38/35 | Morgan, Ruth. — 1922 |
| Folder 38/36 | Morgan, T. H.. — 1927-1933 |
| Folder 38/37 | Morgenthau, Henry. — 1921, 1929 |
| Folder 38/37 | Morris, Edward. — 1925 |
| Folder 39/1 | Morris, Robert T.. — 1932-1933 |
| Folder 39/1 | Morris, Robert T.. — 1941; (to Flexner). |
| Folder 39/2 | Mosenthal, Herman. — 1918 |
| Folder 39/2 | Most, Harry. — 1930 |
| Folder 39/2 | Mott, Fred W.. — 1923 |
| Folder 39/2 | Mott, John R.. — 1920 |
| Folder 39/3 | Mudd, Seeley G.. — 1930 |
| Folder 39/3 | Mudge, Edmund. — 1925 |
| Folder 39/3 | Muir, Robert. — 1931 |
| Folder 39/4 | Muller, Friedrich. — 1910-1932 |
| Folder 39/5 | Mulligan, E. W.. — 1889 |
| Folder 39/5 | Mumford, Edward W.. — 1930 |
| Folder 39/5 | Munn, Aristine P.. — 1931 |
| Folder 39/5 | Munn, James B.. — 1928 |
| Folder 39/5 | Munsey, Frank E.. — 1925 |
| Folder 39/5 | Munson, E. L.. — 1919 |
| Folder 39/5 | Murlin, L. H.. — 1920 |
| Folder 39/6 | Murphree, C. L.. — 1925 |
| Folder 39/6 | Murphy, Starr. — 1919 |
| Folder 39/6 | Murray, J. Lowell. — 1920 |
| Folder 39/6 | Murray, Jenny E.. — 1930 |
| Folder 39/6 | Musser, J. H.. — 1910; (to Thayer). |
| Folder 39/6 | Myers, J. Norris. — 1920 |
| Folder 39/7 | Nadal, E. S.. — 1920 |
| Folder 39/7 | Nauss, Ralph W.. — 1919 |
| Folder 39/8 | Nelbach, George J.. — 1913-1923 |
| Folder 39/9 | Nelson, John M.. — 1930 |
| Folder 39/10 | Nethersole, Olga. — 1926, 1927 |
| Folder 39/11 | Neuberger, Prof. Dr. Max. — 1928 |
| Folder 39/12 | Neufeld, Frederich. — 1927-1932 |
| Folder 39/13 | Neumann, Ignac. — 1931 |
| Folder 39/13 | Newcomer, Harry S.. — 1922 |
| Folder 39/13 | Newman, Sir George. — 1922-1930 |
| Folder 39/14-19 | Newsholme, Arthur. — 1919-1934 |
| Folder 39/20 | Newton, H. A.. — 1870 |
| Folder 39/21 | Newton, Isaac B.. — 1926, 1930 |
| Folder 39/21 | Newton, Isaac S.. — 1870-1874 |
| Folder 39/22 | Nichols, Firmadge K.. — 1929 |
| Folder 39/22 | Nicholson, John R.. — 1920 |
| Folder 39/23 | Nicoll, Matthias. — 1925, 1929 |
| Folder 39/23 | Niehaus, C. H.. — 1930 |
| Folder 39/24 | Noble, Herbert. — 1929 |
| Folder 39/24 | Noguchi, Hideyo. — 1921 |
| Folder 39/24 | Norton, Charles D.. — 1920 |
| Folder 39/25 | Norton, W. W.. — 1932 |
| Folder 39/26 | Novy, F. G.. — 1903 |
| Folder 39/27 | Noyes, Arthur A.. — 1927, 1930 |
| Folder 39/27 | Noyes, Marcia C.. — 1925 |
| Folder 39/28-36 | Nuttall, George H.. — 1886-1933; encl: press clipping photo Welch honorary degree Cambridge University, 1923. |
| Folder 39/37 | Nutting, Mary Adelaide. — 1920 |
| Folder 39/37 | Nydegger, James A.. — 1919-1930 |
| Folder 40/1 | O'Brien, Daniel P.. — 1928-1932 |
| Folder 40/2 | Oertel, Horst. — 1924 |
| Folder 40/2 | Ogata, Tomosaburo. — 1932 |
| Folder 40/2 | Okawa, S.. — 1930 |
| Folder 40/3 | Olcott, Mary W.. — 1906 |
| Folder 40/3 | Oldt, Frank. — 1921 |
| Folder 40/4 | Olin, Richard M.. — 1924, 1925 |
| Folder 40/4 | Oliphant, Herman. — 1929 |
| Folder 40/5 | Oliver, J. C.. — 1920 |
| Folder 40/6-12 | Oliver, John R.. — 1921-1932; encl: reprints "Greek medicine" other historical by JRO in Internat Clin, 1927-1928. |
| Folder 40/13 | Ophuls, W.. — 1903-1929 |
| Folder 40/14-15 | Opie, Eugene L.. — 1894-1925 |
| Folder 40/16 | Oppenheimer, Bernard S.. — 1930-1934 |
| Folder 40/17 | O'Reilly, Robert M.. — 1910; (to Thayer). |
| Folder 40/18-20 | Osborn, Henry F.. — 1910-1934 |
| Folder 40/21 | Osborn, Stanley H.. — 1925 |
| Folder 40/22 | Osler, Grace (Mrs. William, later Lady Osler). — 1928 |
| Folder 40/23-28 | Osler, William. — 1898-1919; encl: obituary tributes, reviews Cushing's Life of WO. |
| Folder 40/29 | Osterhout, W. J.. — 1927 |
| Folder 40/29 | Otis, Elizabeth Morton (Mrs. Theodore C. Otis). — 1920; encl: reprint on "William Morton" by Knopf Boston MSJ, 1920. |
| Folder 40/29 | Ovington, Earle. — 1919; (certificate of flight for William Henry Welch). |
| Folder 41/1 | Packard, Francis R.. — 1927 |
| Folder 41/1 | Padua, Regino G.. — 1922 |
| Folder 41/2 | Padua, Regino G.. — 1922; encl: TMs "Malaria in the Philipines" by RGP 1922. |
| Folder 41/3 | Painter, Charles F.. — 1931 |
| Folder 41/3 | Pallister, William. — 1931 |
| Folder 41/3 | Palmer, Maude (Mrs. Alden J. Bidwell Palmer). — 1920,1933 |
| Folder 41/4 | Palmer, Edward L.. — 1921 |
| Folder 41/4 | Palmer, R. A.. — 1927 |
| Folder 41/4 | Pancoast, Omar. — 1925 |
| Folder 41/4 | Pancoast, Josie (Mrs. Omar Pancoast). — 1929 |
| Folder 41/4 | Paris, William F.. — 1924 |
| Folder 41/5 | Park, Edwards A.. — 1920, 1933 |
| Folder 41/6-7 | Park, Marion E.. — 1931-1932; encl: typed copy Bryn Mawr fund-raising appeal. |
| Folder 41/8-9 | Park, William H.. — 1910-1933 |
| Folder 41/10 | Parran, Thomas Jr.. — 1930 |
| Folder 41/10 | Passano, Edward B.. — 1922 |
| Folder 41/11 | Paton, David. — 1910, 1919 |
| Folder 41/12 | Paton, Stewart. — 1919-1933 |
| Folder 41/13 | Patrick, H. Couper. — 1915 |
| Folder 41/14 | Patterson, Eleanor A. (Mrs. Alexander H. Patterson). — 1930 |
| Folder 41/14 | Patterson, Robert U.. — 1932-1933 |
| Folder 41/15 | Paul, Gustav. — 1920 |
| Folder 41/15 | Paul, John R.. — 1930; encl: reprint "Nathan Smith and typhoid fever" by JRP Yale J Biol Med 2: 168-181, 1930. |
| Folder 41/16 | Paxton, H. C.. — 1921 |
| Folder 41/16 | Payne, John B.. — 1925, 1930 |
| Folder 41/17 | Peabody, George F.. — 1929, 1933 |
| Folder 41/18-19 | Peabody, James E.. — 1928-1934; encl: clippings re yellow fever. |
| Folder 41/20 | Pearce, Rev. Edmund C.. — 1923 |
| Folder 41/21-22 | Pearce, Richard M.. — 1910-1930 |
| Folder 41/23-28 | Pearl, Raymond. — 1919-1922 |
| Folder 42/1-7 | Pearl, Raymond. — 1922-1934 |
| Folder 42/8 | Pearson, R. A.. — 1932 |
| Folder 42/9-11 | Peck, Charles W.. — 1865-1866 |
| Folder 42/12 | Pedersen, Victor C.. — 1920 |
| Folder 42/12 | Peebles, Allon. — 1932 |
| Folder 42/12 | Pelc, Hynek J.. — n.d. |
| Folder 42/13 | Pellegrin, Harold F.. — 1922 |
| Folder 42/13 | Pels, Isaac R.. — 1929, 1932 |
| Folder 42/14 | Penniman, Josiah H.. — 1926, 1930 |
| Folder 42/15 | Pepper, O. H. Perry. — 1930 |
| Folder 42/15 | Perilli, G.. — 1931 |
| Folder 42/16 | Perkins, Elisha H.. — 1920 |
| Folder 42/16 | Perkins, Roger G.. — 1920 |
| Folder 42/17 | Perlstein, Jacob. — 1934 |
| Folder 42/17 | Perry, John H.. — 1871-1928 |
| Folder 42/18 | Peter, W. W.. — 1921-1924; encl: TMs re health campaign in Hangchow China. |
| Folder 42/19 | Peters, William H.. — 1930 |
| Folder 42/19 | Peterson, E. A.. — 1920 |
| Folder 42/20 | Phelps, Carrington. — 1919 |
| Folder 42/20 | Phillips, H. M.. — 1921 |
| Folder 42/21-23 | Phipps, Henry. — 1908-1933 |
| Folder 42/24 | Pierce, C.C.. — 1927-1932 |
| Folder 42/25 | Piersol, George M.. — 1920, 1931 |
| Folder 42/25 | Pierson, Frederick T.. — 1930 |
| Folder 42/25 | Pierson, Mrs. Frederick T.. — 1931 |
| Folder 42/26 | Piggott, Charles S.. — 1922 |
| Folder 42/26 | Pijnan, Michel. — 1931 |
| Folder 42/26 | Pilcher, Lewis S.. — 1930 |
| Folder 42/27 | Pinchot, Gifford. — 1923-1930 |
| Folder 42/27 | Pinchot, Cornelia B. (Mrs. Gifford Pinchot). — 1923 |
| Folder 42/28 | Piper, Adaline D.. — 1919 |
| Folder 42/29-31 | Pirquet, Clemens von. — 1919-1928 |
| Folder 43/1 | Placzek, D.. — 1930 |
| Folder 43/1 | Pleadwell, Capt. F. L.. — 1920-1934 |
| Folder 43/2 | Pleasants, J. Hall. — 1928 |
| Folder 43/3 | Plotz, Harry. — 1928, 1930 |
| Folder 43/3 | Polak, Edward. — 1930 |
| Folder 43/4 | Pollack, Flora. — 1931 |
| Folder 43/4 | Pollitzer, S.. — 1930 |
| Folder 43/4 | Pomeroy, Frank T.. — 1930 |
| Folder 43/5 | Popenoe, Paul. — 1919; encl: TMs re Am Social Hygiene Assoc. |
| Folder 43/6 | Porras, Belisario. — 1920 |
| Folder 43/7 | Porter, Charles. — 1925, 1926 |
| Folder 43/8 | Porter, William H.. — 1920, 1930; encl: reprint "Diabetes" by WHP in Med J Record, 1929. |
| Folder 43/9 | Porter, William T.. — 1897, 1910 |
| Folder 43/10 | Posey, Robert G.. — 1931 |
| Folder 43/10 | Pototzky, Carl. — 1929 |
| Folder 43/10 | Potter, Mary Sargent. — 1926 |
| Folder 43/11-13 | Power, Sir D'Arcy. — 1928-1933 |
| Folder 43/14 | Power, Edward W.. — 1920 |
| Folder 43/14 | Powers, Charles A.. — 1910 |
| Folder 43/15 | Prausnitz, Carl. — 1930 |
| Folder 43/16 | Prescott, Samuel C.. — 1925 |
| Folder 43/17 | Preston, James H.. — 1916-1932 |
| Folder 43/18 | Primrose, A.. — 1930 |
| Folder 43/18 | Prince, Willam D.. — 1921 |
| Folder 43/19-20 | Pritchett, Henry S.. — 1920-1925 |
| Folder 43/21 | Pritchett, Ida W.. — 1922; encl: reprint "Pathologic effects of diphtheria toxin in guinea pig" by IWP in Am J Hygiene. |
| Folder 43/22 | Prizer, Rodney. — 1931 |
| Folder 43/22 | Prudden, T. Mitchell. — 1902, 1910 |
| Folder 43/23 | Pumpelly, Laurence. — 1919 |
| Folder 43/23 | Putnam, Herbert. — 1910; (to Thayer). |
| Folder 43/24 | Quin, Miss ? of Commonwealth Fund. — 1927 |
| Folder 43/24 | Quinby, William C.. — 1930, 1933; encl: program Harvard medical school 150th anniversary, Oct 1933:also notes from WCQ's son sent 1994. |
| Folder 43/24 | Quintard, Edward. — 1910; (to Thayer). |
| Folder 44/1-3 | Radcliffe, Mary M. (Mrs. G. L. Radcliffe). — 1919-1930 |
| Folder 44/4 | Raines, W. G.. — 1922 |
| Folder 44/4 | Rajchman, Ludwik. — 1924-1926 |
| Folder 44/5 | Ramsey, George H.. — 1932 |
| Folder 44/6 | Rand, Frederick V.. — 1926 |
| Folder 44/6 | Randall, Blanchard. — 1910-1929 |
| Folder 44/7 | Randolph, E. D.. — 1919 |
| Folder 44/7 | Raney, M. Llewellyn. — 1919 |
| Folder 44/8-9 | Raney, M. Llewellyn. — 1920-1931 |
| Folder 44/10 | Rankin, W. S.. — 1925 |
| Folder 44/10 | Ransdell, Sen. Joseph E.. — 1927, 1931 |
| Folder 44/11-13 | Ransdell, Sen. Joseph E.. — 1931-1933 |
| Folder 44/14 | Raper, Howard R.. — 1927 |
| Folder 44/14 | Rappard, William E.. — 1920 |
| Folder 44/14 | Rathbun, R.. — 1909 |
| Folder 44/15 | Ravenel, Mazyck P.. — 1921 |
| Folder 44/16 | Raynor, H. C.. — 1925 |
| Folder 44/16 | Read, Florence M.. — 1924-1927 |
| Folder 44/17 | Read, Florence M.. — 1932 |
| Folder 44/17 | Read, Katherine L.. — 1930 |
| Folder 44/18 | Reder, Francis and Mrs. F. Reder. — 1930 |
| Folder 44/18 | Reece, Richard J.. — 1916 |
| Folder 44/18 | Reed, Charles A. L.. — 1921 |
| Folder 44/18 | Reed, Lowell J.. — 1919 |
| Folder 44/18 | Reed, Emilie (Mrs. Walter Reed). — 1922 |
| Folder 44/19-20 | Reeve, Gen. Charles McC. ("Gaff"). — 1930-1934 |
| Folder 44/21 | Regaud, C. V.. — 1929 |
| Folder 44/21 | Reid, Edith G. (Mrs. H. Fielding Reid). — 1919-1933 |
| Folder 44/21 | Reid, Esther A.. — 1922? |
| Folder 44/22 | Reik, Henry A.. — 1919 |
| Folder 44/22 | Reimers, Marx. — 1930 |
| Folder 44/22 | Reiss, Rudolf. — 1933 |
| Folder 44/23 | Remsen, Ira, President Johns Hopkins. — 1902-1910; encl: card re Woodrow Wilson. |
| Folder 44/23 | Remsen, Mrs. Ira. — 1930 |
| Folder 44/24 | Rettger, Leo F.. — 1921 |
| Folder 44/24 | Reynolds, S. M.. — 1922 |
| Folder 44/25 | Rhees, Rush. — 1920, 1921 |
| Folder 44/26 | Rice, Calvin W.. — 1930 |
| Folder 44/26 | Richards, A. N.. — 1930 |
| Folder 44/26 | Richards, B.U.. — 1925 |
| Folder 44/26 | Richardson, Charles W.. — 1910; (to Thayer). |
| Folder 44/27-28 | Riesman, David. — 1919-1933 |
| Folder 44/29 | Riker, Thad W.. — 1932 |
| Folder 44/29 | Riley, Henry A.. — 1934 |
| Folder 44/30 | Riley, R. H.. — 1929-1933 |
| Folder 44/31 | Ritchie, Albert C.. — 1925-1934; (Governor State of Maryland). |
| Folder 44/32 | Ritchie, Harry P.. — 1932 |
| Folder 44/32 | Riviere, R. Dujarric. — 1930 |
| Folder 44/32 | Rixey, Rear Adm. Presley M.. — 1910, 1924 |
| Folder 44/33 | Rixford, Emmet. — 1931 |
| Folder 44/33 | Robertson, H. E.. — 1930 |
| Folder 44/33 | Robertson, William E.. — 1930 |
| Folder 44/34 | Robinson, G. Canby. — 1920-1932 |
| Folder 44/35 | Robinson, Henry M.. — 1930 |
| Folder 44/35 | Robinson, J. W. Dudley. — 1931 |
| Folder 44/35 | Robinson, Victor. — 1921 |
| Folder 44/36 | Robinson, William D.. — 1920-1921 |
| Folder 44/37 | Robson, Arthur W.. — 1927 |
| Folder 44/37 | Rochester, E. S.. — 1922 |
| Folder 45/1 | Rockefeller, John D. Jr.: list of Welch's correspondence with JDR Jr. sent to Dr. Flexner. — Oct. 1935 |
| Folder 45/2-23 | Rockefeller, John D. Jr.. — 1901-1934 |
| Folder 45/24 | Roddis, Louis H.. — 1930 |
| Folder 45/24 | Rogers, Agnes L.. — 1922 |
| Folder 45/24 | Rogers, Frances J. (Mrs. Henry W. Rogers). — 1920 |
| Folder 45/25 | Rohrer, C. W. G.. — 1921, 1932 |
| Folder 45/25 | Rolleston, Sir Humphrey. — 1916-1930 |
| Folder 45/26 | Roos, Charles F.. — 1932 |
| Folder 45/26 | Roosevelt, President Theodore. — 1904 |
| Folder 45/27 | Root, Edward W.. — 1929 |
| Folder 45/27 | Root, Grace (Mrs. Edward W. Root). — 1931-1934 |
| Folder 45/28 | Root, Sen. Elihu. — 1910-1930 |
| Folder 45/28 | Root, Alida S. (Mrs. Elihu Root). — 1933 |
| Folder 45/29 | Root, Aida (Mrs. Oren Root). — 1925 |
| Folder 45/29 | Root, Francis M.. — 1923 |
| Folder 45/30 | Ros, Arturo R.. — 1931 |
| Folder 45/30 | Rose, Wickliffe. — 1914 |
| Folder 45/31-36 | Rose, Wickliffe. — 1915-1931; encl: data re Rockefeller Foundation. |
| Folder 46/1 | Rosenbach, A. S. W.. — 1933 |
| Folder 46/1 | Rosengarten, I. G.. — 1920 |
| Folder 46/1 | Rosenow, E. C.. — 1928 |
| Folder 46/1 | Rosenstein, Leo. — 1933 |
| Folder 46/2 | Rosenwald, Julius. — 1925-1930 |
| Folder 46/3-4 | Ross, Sir Ronald. — 1923-1931; encl: program dinner celebrating anniversary "Mosquito Day" London, Aug 1931. |
| Folder 46/5-6 | Rous, Peyton. — 1926-1934 |
| Folder 46/7 | Roussy, Gustav. — 1926 |
| Folder 46/7 | Roux, E.. — 1910, 1919 |
| Folder 46/8 | Rowe, Allan Winter. — 1930 |
| Folder 46/8 | Rowe, L. S.. — 1924, 1929 |
| Folder 46/9 | Rowland, J. M. H.. — 1919-1932 |
| Folder 46/10 | Rowley, Francis H.. — 1899 |
| Folder 46/10 | Rowntree, Leonard G.. — 1930-1933 |
| Folder 46/11 | Ruggles, Arthur H.. — 1925-1930 |
| Folder 46/12 | Rushmore, Stephen. — 1921, 1922 |
| Folder 46/13 | Rusk, George Y.. — 1924 |
| Folder 46/14-28 | Russell, Frederick F.. — 1919-1934 |
| Folder 46/29 | Ruzicka, Stan.. — 1931 |
| Folder 46/29 | Ryerson, Martin. — 1930 |
| Folder 46/29 | Rytina, A. G.. — 1920 |