- Allen, James, 1806-18461
- Allen, R. C. (Rolland Craten), 1881-19481
- Allis, Edward P. (Edward Phelps),1824-18891
- Almada, André Álvares d'1
- Alpha Phi Omega1
- Alsop, John, 1724-17941
- Alton Democrat (Firm)1
- American Automobile Association1
- American Baptist Mission Press1
- American Board of Commissioners for Foreign Missions1
- American Coal & Coke Corporation.1
- American Express Company1
- American Lithographing and Printing Company, Des Moines.1
- American Loan & Trust Company1
- American Union Telegraph Company1
- Amstutz, N. S. (Noah Steiner), 1864-1
- Amundson, H. C1
- Amy, M. S. (Surveyor)1
- Anderson, A. H. (Andrew H.)1
- Anderson, G. W. (Publisher)1