It was commissioned by the French Minister of War, Etienne-Francois, who probably wanted something more practical than horses for hauling large artillery. Cugnot and another military mechanic, Brezin, assembled the first car at the Paris Arsenal. The biggest challenge was to redirect the lateral motion of a steam engine into forward motion. They placed the engine and boiler above the front wheel and used two pistons to push notched discs on each side of the front wheel. It must have been extremely difficult to steer.
Even the lowliest of electric vehicles from the modern era could best the steamer's 4 km/h top speed or 15 minute range, but the five ton tow capacity was quite respectable and after further development, a 4 passenger version was even introduced. One thing the Cugnot vehicle lacked, however, was brakes. Perhaps an oversight by the team, but it should come as no surprise that besides being the first self-propelled vehicle, it was also the first vehicle to be in an accident. By 1771, the project was mothballed. Although others fiddled with steam powered vehicles in ensuing years, it wasn't until Gottlieb Daimler developed the internal combustion engine 115 years later, that automobiles became viable again. Follow the read link for the full writeup and many more high-res images.