Collection
- Archibald Philip Primrose, 5th Earl of Rosebery journal, 18731
- Archibald Rhind diary, 1833-18391
- Arthur H. Vandenberg papers, 1884-1974 (majority within 1915-1951)1
- Arthur J. Lacy Papers, 1891-19751
- Arthur J. Tuttle Papers, 1849-1958 (majority within 1888-1944)1
- Arthur Lyon Cross Papers, 1897-19401
- Arthur W. Haydon diaries, 1865-1879, 1888-19151
- Asa Waldo Wildes daybook, 1849-1864 (majority within 1857)1
- Asenath Chapin diaries, 1840-18631
- Augusta (Me.) woman's journal, 1852-18531
- Austin Blair Family Papers, 1849-1981 (majority within 1895-1920)1
- Austin E. Lyon diary, 1862-1866 (majority within 1863)1
- B. Whitney travel diary, 18161
- B. Woodruff diary, 18841
- Barbara Bassett McIver papers, 1961-2011 (majority within 1961-1964)1
- Barber G. Buell papers, 1760-1935 (majority within 1849-1899)1
- Beatty family papers, 1831-18861
- Bechtold family papers, [ca. 1847-ca. 1907 scattered dates]1
- Beeson family papers, 1765-1956 (majority within 1765-1898)1
- Bela Hubbard papers, 1837-18931