On October 20, 1902, the first Cadillac was assembled (although some sources say October 16 or 17th). This photograph shows men wearing aprons, overalls, and suits gathered around what is noted as “the first ‘Cadillac’ about to start for the first time on its own power.”
Cadillac was formed from the remnants of the Henry Ford Company. After a dispute between Henry Ford and his investors, Ford left the company along with several of his key partners in March 1902. Ford’s financial backers William Murphy and Lemuel Bowen called in engineer Henry M. Leland of Leland & Faulconer Manufacturing Company to appraise the plant and equipment in preparation for liquidating the company’s assets. Instead, Leland persuaded the pair to continue manufacturing automobiles using Leland’s proven single-cylinder engine. A new company called the Cadillac Automobile Company was established on 22 August 1902, re-purposing the Henry Ford Company factory at Cass Street and Amsterdam Avenue. It was named after French explorer Antoine Laumet de La Mothe, sieur de Cadillac, who had founded Detroit in 1701.
Cadillac’s first automobiles, the Runabout and Tonneau, were completed in October 1902. They were two-seat horseless carriages powered by a 10 hp (7 kW) single-cylinder engine. They were practically identical to the 1903 Ford Model A. Many sources say the first car rolled out of the factory on 17 October; in the book Henry Leland—Master of Precision, the date is 20 October; another reliable source shows car number three to have been built on 16 October. Cadillac displayed the new vehicles at the New York Auto Show in January 1903, where the vehicles impressed the crowds enough to gather over 2,000 firm orders. Cadillac’s biggest selling point was precision manufacturing, and therefore, reliability; a Cadillac was simply a better-made vehicle than its competitors.
Source : Cadillac Wikipedia Entry