Cadillac Motor Company began with the remnants of Henry Ford’s second, failed business, and became the premier luxury car company it is today. It is second only to Buick as the oldest active car marker in the U.S. Its founder, Henry Leland, convinced former Ford board of directors.
On August 27, 1902 the Cadillac Automobile Company was launched, named after Detroit founder Antoine de la Mothe Cadillac, with Leland as director. He used the Leland and Faulconer factory started by Leland in 1894 to tool bicycles and marine engines. By 1899 it was making automobile engines for Ransom Olds.
The first Cadillac cars used a Ford designed body with Leland’s Cadillac engine. They were promoted at the 1903 New York Auto Show, and sales manager William Metzger took over 1000 orders. By 1904 Leland and his son Wilfred, who left his pursuit of a medical career to join his father in the automotive business, assumed day-to-day operation of the company. In 1905 they consolidated Leland & Faulconer, where the car engines were being made, with Cadillac, turning it into one operation renamed Cadillac Motor Company.
A George Mason-designed building was constructed at Amsterdam Street and Cass Avenue, and manufacture and assembly now took place in one location. Cadillac was known for the interchangeability and precision of its parts. It won the British Dewar trophy for automotive innovation in 1908 when mechanics disassembled three Cadillacs, mixed the parts with other stock parts, then reassembled and successfully drove the cars for 500 miles without incident.
By the time General Motors acquired the company in 1909, Cadillac had become one of America's leading luxury automakers. Cadillac, “The Standard of the World,” made several notable contributions to automotive manufacturing including: the production of a fully enclosed car, in quantity, by 1906; the first to offer electric starting, ignition, and lighting in cars; development of some of the most powerful V-8, V-12, and V-16 engines in the industry; and design of an all-steel roof in 1935.
According to detroithistorical.org & Wikipedia