In 1868 the Brill company was founded as J.G. Brill and Sons. After James Rawle joined the firm in 1872 it was renamed J.G. Brill & Company.
In 1902 Brill bought out the American Car Company; in 1904 G. C. Kuhlman Car Company and John Stephenson Company; and in 1907 Wason Manufacturing Company. Brill acquired a controlling share of the Danville Car Company in 1908, dissolving it in 1911, and Canadian railway car builder Preston Car Company in 1921, which ceased operating in 1923. In 1926 American Car and Foundry Company acquired a controlling interest in what had become the Brill Corporation. The new structure consisted of:
- ACF Motors Company, which owned Hall-Scott Motor Car Company (100%) and controlled 90% of Fageol Motors; and
- the J.G. Brill Company.
In 1944 these two companies merged, forming the ACF-Brill Motors Company.
In the same year, ACF-Brill licensed Canadian Car and Foundry of Montreal to manufacture and sell throughout Canada motor buses and trolley coaches of their design as Canadian Car-Brill. The firm built about 1,100 trolley buses and a few thousand buses under the name. Brill had earlier (in 1908) established a company in France (Cie. J.G. Brill of Gallardon, which was sold to Electroforge in 1935.
In 1946 Consolidated Vultee Aircraft Corporation acquired a controlling interest in ACF-Brill for $7.5 million. Consolidated Vultee was sold the following year to the Nashville Corporation, which in 1951 sold its share to investment firm Allen & Co. In early 1954, the Brill name disappeared when ACF-Brill ceased production and subcontracted its remaining orders.
Brill granted licenses to build its vehicles to the Canadian Car and Foundry (Peter Witt streetcars, trolley buses and motor buses) and the South Australian Railways (Model 75 railcars).