Formed on July 22nd, 1908 by two brothers: Fred J. and Charles T. Fisher, with their uncle Albert Fisher. It was a Detroit carriage maker.
Cadillac gave the Fishers their first major order for closed bodies (150 of them) in 1910 and by 1916 it was building 100,000 bodies a year, including for Cadillac. General Motors bought a controlling interest in the corporation in 1919; that year they made all open and closed bodies for Cadillac. Fisher adopted the Napoleonic coach as its emblem on 10 July, 1923. GM completed the purchase of the Fisher Body Corp. in 1926 forming the Fisher Body Division of GM.
Sources
http://www.car-nection.com/cadillacdatabase