| File 68/1-15 | William Henry Welch to William Wickham Welch (father). 1869-1891 |
| Folder 68/1 | 1869 |
| Folder 68/2 | 1873 |
| Folder 68/3 | 1874 |
| Folder 68/4 | 1875 |
| Folder 68/5 | 1876 |
| Folder 68/6 | 1877 |
| Folder 68/7 | 1878 |
| Folder 68/8 | 1880 |
| Folder 68/9 | 1881 |
| Folder 68/10 | 1883 |
| Folder 68/11 | 1884 |
| Folder 68/12 | 1885 |
| Folder 68/13 | 1889 |
| Folder 68/14 | 1890 |
| Folder 68/15 | 1891 |
| File 68/16-25 | William Henry Welch to Emily Sedgwick Welch (stepmother). 1876-1901 |
| Folder 68/16 | 1876 |
| Folder 68/17 | 1877 |
| Folder 68/18 | 1879-1884 |
| Folder 68/19 | 1885-1886 |
| Folder 68/20 | 1890-1891 |
| Folder 68/21 | 1892 |
| Folder 68/22 | 1893 |
| Folder 68/23 | 1894-1895 |
| Folder 68/24 | 1897-1899 |
| Folder 68/25 | 1900-1901 |
| File 68/26-29 | William Henry Welch to Emma Alice Welch (sister). 1861-1866 |
| Folder 68/26 | 1861-1863 |
| Folder 68/27 | 1864 |
| Folder 68/28 | 1865 |
| Folder 68/29 | 1866 |
| File 69/1-70/7 | William Henry Welch to Emma Alice Welch Walcott (sister). 1866-1909 |
| Folder 69/1 | 1866-1870 |
| Folder 69/2 | 1870-1876 |
| Folder 69/3 | 1876, Apr to Dec |
| Folder 69/4 | 1877 |
| Folder 69/5 | 1878 |
| Folder 69/6 | 1879 |
| Folder 69/7 | 1880 |
| Folder 69/8 | 1881 |
| Folder 69/9 | 1882 |
| Folder 69/10 | 1883 |
| Folder 69/11 | 1884 |
| Folder 69/12 | 1885 |
| Folder 69/13 | 1886 |
| Folder 69/14 | 1887 |
| Folder 69/15 | 1888 |
| Folder 69/16 | 1889 |
| Folder 69/17 | 1890 |
| Folder 69/18 | 1891 |
| Folder 69/19 | 1892 |
| Folder 69/20 | 1893 |
| Folder 69/21 | 1894 |
| Folder 69/22 | 1895 |
| Folder 69/23 | 1896 |
| Folder 69/24 | 1897 |
| Folder 69/25 | 1898 |
| Folder 69/26 | 1899 |
| Folder 69/27 | 1900 |
| Folder 69/28 | 1901 |
| Folder 69/29 | 1902 |
| Folder 69/30 | 1865-1899 |
| Folder 70/1 | 1903 |
| Folder 70/2 | 1904 |
| Folder 70/3 | 1905 |
| Folder 70/4 | 1906 |
| Folder 70/5 | 1907 |
| Folder 70/6 | 1908 |
| Folder 70/7 | 1909 |
| File 70/8-29 | William Henry Welch to Elizabeth (Walcott) Kellogg (Bessie), daughter of Emma, niece of WHW. 1902-1933 |
| Folder 70/8 | 1902-1906 |
| Folder 70/9 | 1907 |
| Folder 70/10 | 1908-1909 |
| Folder 70/11 | 1910 |
| Folder 70/12 | 1911 |
| Folder 70/13 | 1912 |
| Folder 70/14 | 1913 |
| Folder 70/15 | 1914 |
| Folder 70/16 | 1915 |
| Folder 70/17 | 1916 |
| Folder 70/18 | 1918 |
| Folder 70/19 | 1919 |
| Folder 70/20 | 1920 |
| Folder 70/21 | 1921 |
| Folder 70/22 | 1924 |
| Folder 70/23 | 1925 |
| Folder 70/24 | 1927 |
| Folder 70/25 | 1928 |
| Folder 70/26 | 1929 |
| Folder 70/27 | 1931 |
| Folder 70/28 | 1932 |
| Folder 70/29 | 1933 |
| File 70/30-37 | William Henry Welch to other nephews and nieces. 1909-1933 |
| Folder 70/30-31 | 1909, 1923 |
| Folder 70/32-36 | 1901-1933 |
| Folder 70/37 | 1933 |
| File 71/1-9 | Emeline Collin Welch. 1831-1850 and n.d. |
| Folder 71/1-4 | 1831-1839 and n.d. |
| Folder 71/5-9 | 1846-1850 |
| File 71/10-13 | Emily Sedgwick Welch, stepmother, to WHW. 1864-1892 |
| Folder 71/10 | 1864-1866 |
| Folder 71/11 | 1867 |
| Folder 71/12 | 1869 |
| Folder 71/13 | 1892 |
| File 71/14-20 | Correspondence of William Wickham Welch, father |
| Folder 71/14 | 1838-1839 |
| Folder 71/15-16 | 1843-1850 |
| Folder 71/17 | 1850-1856 |
| Folder 71/18-19 | 1864-1871 |
| Folder 71/20 | 1888 |
| File 71/21-72/7 | Emily Alice Welch Walcott (Emma), sister, to WHW. 1864-1909 |
| Folder 71/21 | 1864, Jan |
| Folder 71/22 | 1864, Feb |
| Folder 71/23 | 1864, Mar |
| Folder 71/24 | 1864, May |
| Folder 71/25 | 1864, Jun |
| Folder 71/26 | 1864, Jul-Oct |
| Folder 71/27 | 1864, Nov-Dec |
| Folder 71/28 | 1865, Jan |
| Folder 71/29 | 1865, Feb |
| Folder 71/30 | 1865, Mar |
| Folder 71/31 | 1865, May |
| Folder 71/32 | 1865, Jun-Oct |
| Folder 71/33 | 1866, Feb-Mar |
| Folder 71/34 | 1866, Apr-May |
| Folder 71/35 | 1866, Jul-Sep |
| Folder 72/1 | 1866, Oct-Nov |
| Folder 72/2 | 1866-1867 |
| Folder 72/3 | 1867-1868 |
| Folder 72/4 | 1869 |
| Folder 72/5 | 1903 |
| Folder 72/6 | 1909 |
| Folder 72/7 | 1850-1863 |
| File 72/8-23 | Elizabeth Walcott Kellogg, niece to WHW. 1915-1934 |
| Folder 72/8 | 1915-1919 |
| Folder 72/9 | 1919-1920 |
| Folder 72/10 | 1920, Apr-May |
| Folder 72/11 | 1920, Aug-Dec |
| Folder 72/12 | 1921 |
| Folder 72/13 | 1923, Apr |
| Folder 72/14 | 1923-1927 |
| Folder 72/15 | 1928, Apr |
| Folder 72/16 | 1928-1930 |
| Folder 72/17 | 1930, Feb-Apr |
| Folder 72/18 | 1930-1931 |
| Folder 72/19 | 1931, Apr-Jul |
| Folder 72/20 | 1932 |
| Folder 72/21 | 1932, Dec-Feb 1933 |
| Folder 72/22 | 1933, Mar-Nov |
| Folder 72/23 | 1934 |
| File 72/24-74/13 | Other nephews, nieces, grand nephews and nieces |
| Folder 72/24-26 | 1910-1922 |
| Folder 72/27-29 | 1918-1933 |
| Folder 72/30 | 1923 |
| Folder 72/31 | 1930 |
| Folder 73/1-9 | 1917-1934 |
| Folder 73/10-11 | 1921-1932 |
| Folder 73/12-13 | 1920-1930 |
| Folder 73/14 | 1933 |
| Folder 73/15 | 1932-1942 |
| Folder 73/16 | 1920 |
| Folder 73/17-34 | 1910-1932 |
| Folder 74/1-6 | 1932-1934 |
| Folder 74/7-9 | 1921-1931 |
| Folder 74/10-11 | 1910-1934 |
| Folder 74/12 | 1919-1933 |
| Folder 74/13 | 1930-1933 |
| File 74/14-75/22 | Cousins, other relatives |
| Folder 74/14 | 1930-1933 |
| Folder 74/15 | 1864-1920 |
| Folder 74/15 | 1863-1864 |
| Folder 74/16 | 1920 |
| Folder 74/16 | 1864-1920 |
| Folder 74/17 | |
| Folder 74/17 | 1919-1931 |
| Folder 74/18 | 1933 |
| Folder 74/19 | 1865-1933 |
| Folder 74/20 | 1867 |
| Folder 74/20 | 1920-1930 |
| Folder 74/21 | 1920 |
| Folder 74/21 | 1931 |
| Folder 74/22 | 1929-1934 |
| Folder 74/23-24 | 1920-1933 |
| Folder 74/25 | 1929 |
| Folder 74/26-28 | 1919-1930 |
| Folder 74/29 | 1925 |
| Folder 74/30 | 1926-1931 |
| Folder 75/1 | 1866 |
| Folder 75/1 | 1870 |
| Folder 75/1 | 1930, (all cousins) |
| Folder 75/2 | 1930 |
| Folder 75/3 | 1920-1933 |
| Folder 75/4 | 1865, 1866 |
| Folder 75/5 | 1864-1866 |
| Folder 75/6 | 1930 |
| Folder 75/6 | 1907-1908 |
| Folder 75/7 | 1908-1922 |
| Folder 75/8 | 1918 |
| Folder 75/9 | 1929 |
| Folder 75/10 | 1866 |
| Folder 75/11 | 1930 |
| Folder 75/11 | 1931 |
| Folder 75/12 | 1864 |
| Folder 75/12 | 1930 |
| Folder 75/13-14 | 1864-1866 |
| Folder 75/15 | 1930 |
| Folder 75/16-18 | 1864-1865 |
| Folder 75/19 | 1865 |
| Folder 75/20 | 1866-1919 |
| Folder 75/20 | 1921 |
| Folder 75/20 | 1921-1929 |
| Folder 75/21 | 1920 |
| Folder 75/21 | 1931 |
| Folder 75/22 | 1865-1866 |