- Assier, Adolphe d', 1827-1889 author1
- Associated Charities of Boston, author.1
- Association of Medical Superintendents of American Institutions for the Insane.1
- Association of Military Surgeons of the United States, author.4
- Association of Military Surgeons of the United States.2
- Asylum for Orphan Girls (London, England)2
- Atchison, T. A. (Thomas Ayers), 1818-19001
- Atkinson, Donald T. (Donald Taylor), 1874-1959 author1
- Atkinson, Edward, 1827-19051
- Atkinson, Edward, 1827-1905, author2
- Atkinson, I. Edmondson (Isaac Edmondson), 1846-1906 author1
- Atkinson, William Walker, 1862-1932 author1
- Atlee, Washington L. (Washington Lemuel), 1808-18781
- Atomic Bomb Casualty Commission, author.1
- Attwell, Mabel Lucie, 1879-1964, artist1
- Atwater, Caleb, 1778-18671
- Atwater, W. O. (Wilbur Olin), 1844-1907, author1
- Atwool, Courtenay.1
- Aubry, Charles.1
- Auerbach, John, author1