Allis-Chalmers was a U.S. manufacturer of machinery for various industries. Its business lines included agricultural equipment, construction equipment, power generation and power transmission equipment, and machinery for use in industrial settings such as factories, flour mills, sawmills, textile mills, steel mills, refineries, mines, and ore mills. The first Allis-Chalmers Company was formed in 1901 as an amalgamation of the Edward P. Allis Company (steam engines and mill equipment), Fraser & Chalmers (mining and ore milling equipment), the Gates Iron Works (rock and cement milling equipment), and the industrial business line of the Dickson Manufacturing Company (engines and compressors). It was reorganized in 1912 as the Allis-Chalmers Manufacturing Company.
Immediately at the war's end, in 1945–1946, Allis-Chalmers endured a crippling 11-month labor strike.
During the next 70 years its industrial machinery filled countless mills, mines, and factories around the world, and its brand gained fame among consumers mostly from its farm equipment business's orange tractors. In the 1980s and 1990s a series of divestitures transformed the firm and eventually dissolved it. Its successors today are Allis-Chalmers Energy and AGCO.