- Ambrose E. Barnes & Bro.1
- American Bank Note Company1
- American Card Clothing Co.1
- American Copper Brass & Iron Works1
- American Glass Company1
- American Grocery Company4
- American Mills1
- American Novelty Cloak Co.1
- American Rubber Co.2
- American Supply Co.1
- American Surety Company4
- American Tube & Stamping Co.1
- American Wholesale Corporation1
- Amherst College. Library4
- Amor Building Corp.1
- Ampir Realty Corp.1
- Anderson & Krum Stationery Co.2
- Anderson, Sargent & Co.1
- Andrew Dutton1
- Andrew J. Joyce, Carriage Manufacturer1
- Annal Co.1
- Anru Realty Corp.1
- Ansie Realty Corp.1
- Anthony Campagna and Sons12
- Anthony Properties, Inc.1
- Antoni Tadross & Co.1
- Appel, Henry J.2
- Arbeit, Arnold A.9
- Arbuckle Bros.2
- Arbuckles & Co.1
- Arbuthnot, Stephenson & Co.1
- Architects Design Group3
- Architects and Engineers Affiliates1
- Ardale Building Corp.1
- Ardlan Construction Co., Inc.1
- Argus Company1
- Arkell Weekly Co.1
- Armory Estates, Ltd.5
- Armstrong, Lorenzo D.1
- Arnley Construction Co., Inc.1
- Arno Realty Corp.1
- Arnold M. Goldman and Co., Inc.12
- Art Stove Company1
- Artcourt Realty Co.1
- Arthold Realty Co.1
- Arthur & Bonnell1
- Arthur Hardgrove Co.12
- Artpaul Realty Co., Ltd.9
- Artsis, Jerome M.2
- Arwin Construction Corp.1
- Asher Dann and Sons3
- Asher Dann and Sons, Inc.3
- Ashley Apartments, Inc.2
- Ashwood Realty Corp.1
- Astor House9
- Astor, Vincent9
- Atchison Foundry Works1
- Atlantic Hotel2
- Atlantic Towers, Inc.3
- Atlas and Son1