A
- ABC (1906–1910)
- ABC (1922)
- Abbott-Detroit (1909–1916; Abbott 1917-1918)
- Able (1917–1919)
- Ace (1920–1922)
- Acme (1903–1911)
- Adams-Farwell (1899–1912)
- Adria (1921–1922)
- A.E.C. (or Anger) (1913–1915)
- Aerocar (1905–1908)
- Aero Car (1921)
- Aerocar (1946)
- Aero-Type (Victor Page model)
- Ahrens-Fox (1913)
- Airscoot (1947)
- Airway (1949–1950)
- Ajax (1914–1915)
- Ajax (1920–1921)
- Ajax (1925–1926)
- Ajax Electric (1901–1903)
- Aland (1916–1917)
- Albany (1907–1908)
- Albatross (1939)
- ALCO (1909–1913)
- Alden-Sampson (1904, 1911)
- Aldo (1910–1911)
- Alena Steam Car (1922)
- All-Steel (1915–1916)
- Allen (1913–1922)
- Allen (1913–1914)
- Allen Kingston (1907–1910)
- Allis-Chalmers (before 1919)
- Allstate (1952–1953)
- Alpena (1910–1914)
- Alsace (1920–1921)
- Alter (1914–1917)
- Altham (1896–1899)
- Altman (1901)
- Aluminum (1920–1922)
- Amalgamated (1917–1919)
- Ambassador (1921–1925)
- Amco (1917–1922)
- America (1911)
- American (1899)
- American (1902–1903)
- American (1906–1914)
- American (1911–1912)
- American (1914)
- American (aka American (Balanced) Six) (1917–1924)
- American Austin (1929–1934; American Bantam 1938-1941)
- American Beauty (1918–1920) (see Pan-American)
- American Berliet (1906–1908)
- American Chocolate (1903–1906)
- American De Dion (1900–1901)
- American Electric (1896–1902)
- American Electric (1913–1914)
- American Fiat (1910–1918)
- American Gas (1902–1904)
- American Junior (1916–1920)
- American Juvenile Electric (1907)
- American Locomotive (1906–1913)
- American Mercedes (1904–1907)
- American Mors (1906–1909)
- American Motors (or AMC) (1966–1987)
- American Napier (1904–1912)
- American Populaire (1904–1905)
- American Power Carriage (1899–1900)
- American Simplex (1906–1910; Amplex 1910-1913)
- American Steam Car (1924–1931)
- American Steamer (1922–1924)
- American Tri-Car (1912)
- American Underslung (1905–1914)
- American Waltham (1898–1899)
- American Wheelock
- Ames (1910–1915)
- Ams-Sterling (1917)
- Anahuac (1922)
- Anchor Buggy (1910–1911)
- Anderson (1907–1910)
- Anderson (1916–1925)
- Anger (see A.E.C.)
- Angus (see Fuller)
- Anheuser-Busch (1905)
- Anhut (1909–1910)
- Ann Arbor (1911–1912)
- Anna (1912)
- Ansted (1926–1927)
- Ansted-Lexington (1922)
- Anthony (1899–1900)
- Apollo (1906–1907)
- Apollo (1962–1964)
- Apperson (1902–1926)
- Apple (1917–1918)
- Aptera Motors (2005-2011)
- Arabian (1915–1917)
- ArBenz (1911–1918)
- Ardsley (1905–1906)
- Argo (1914–1916)
- Argo Electric (1912–1916)
- Argonne (1919–1920)
- Ariel (1905–1907)
- Aristos (see Mondex-Magic)
- Armstrong Electric (1885–1902)
- Arnolt (1953–1954)
- Arrow Cyclecar (1914)
- Artzberger (1904)
- Astra (1920)
- Atlas (1906–1907)
- Atlas (1907–1911; Atlas-Knight 1912-1913)
- Auburn (1900–1936)
- Auburn (1912–1915)
- Aultman (1901)
- Aurora (1905–1906)
- Aurora (1907–1909)
- Aurora (1957–1958)
- Austen (see Roper)
- Austin (1901–1921)
- Auto-Bug (1909–1910)
- Auto Cub (1956)
- Autocar (1900–1912)
- Auto Cycle (1906–1907)
- Auto Dynamic (1900–1902)
- Autoette (1910–1913)
- Autoette (1948–1970)
- Automatic (1921)
- Automobile Fore Carriage (1900)
- Automobile Voiturette (see Gasmobile)
- Automotor (1901–1904)
- Auto Parts (see King-Remick)
- Auto Tricar (1914)
- Auto Two (see Buffalo)
- Auto Vehicle (see Tourist)
Read more about this topic: List Of Defunct Automobile Manufacturers Of The United States