- American Print Works1
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- Ames, Fisher, 1758-18081
- Anderson, Alexander, 1775-18702
- Anderson, James1
- Anderson, Martin Brewer, 1815-18901
- Andrews, Ebenezer Turrell, 1766-18511
- Andrews, G. H. 1816-18981
- Andrews, William Loring, 1837-19206
- Annand, Douglas, 1903-19761
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- Anthony, A. V. S. 1835-19061
- Anthony, Susan B. 1820-19061
- Anti-Protective Tariff League of Minnesota1
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- Appel, Joseph H. 1873-19491
- Appleton Press1
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- Ashburner, Charles A. 1854-18891
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- Astor, William B. 1792-18751
- Ateshoglou, A. D1
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- Atwater, W. O. 1844-19071
- Atwell, Benjamin H1
- Automobile Club of New York1
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- Bacon, Edgar Mayhew, 1855-19352
- Bacon, Edmund N1
- Bader, Louis, 1921-1