Between 1899 and 1902 there were 2 prototype vehicles built in Detroit, Michigan by Walter Marr. Some documentation exists of the 1901 or 1902 prototype with tiller steering similar to the Oldsmobile Curved Dash.
In mid 1904 another prototype was constructed for an endurance run which convinced James H. Whiting to authorize production of the first models offered to the public. The architecture of this prototype was the basis for the Model B.
The first Buick made for sale, the 1904 Model B, was built in Flint, Michigan. There were 37 Buicks made that year, none of which survive.
There are, however, two replicas in existence: the 1904 endurance car at the Buick Gallery & Research Center in Flint, and a Model B assembled by an enthusiast in California for the division's 100th anniversary. Both of these vehicles use various parts from Buicks of that early era as well as fabricated parts. It is important to note these vehicles were each constructed with the two 1904 engines known to exist.
The powertrain and chassis architecture introduced on the Model B was continued through the 1909 Model F. The early success of Buick is attributed in part to the valve-in-head engine patented by Eugene Richard. The creation of General Motors is attributed in part to the success of Buick, so it can be said Marr and Richard's designs directly led to GM.
The basic architecture of the 1904 Buick was optimally engineered even by today's standards. The flat-twin engine is inherently balanced, with torque presented to the chassis in a longitudinal manner - actually cancelling front end lift - rather than producing undesirable lateral motion. The engine was mounted amidships, now considered the optimal location.
Durant was a natural, and Buick soon became the largest car maker in America. Using the profits from this, Durant embarked on a series of corporate acquisitions, calling the new mega-corporation General Motors. At first, the manufacturers comprising General Motors competed against each other, but Durant ended that. He wanted each General Motors division to target one class of buyer, and in his new scheme Buick was near the top—only the Cadillac brand had more prestige. This is the position Buick occupies to this day in the GM lineup.