(A Biography entry Available online in Kids InfoBits.)
It's difficult to define an automobile, but many people credit Cugnot with building the first one in 1769. Powered by a steam engine, it was a three-wheeled vehicle designed to pull field artillery. It carried four people and had a top speed of about 2.5 miles per hour (4 kph). Every 20 minutes or so it had to stop to build up a new head of steam in the boiler.
Cugnot built a second steam-driven car in 1770. One day, Cugnot took one of his cars out for a drive along the cobblestone streets of Paris and ran into a stone wall, producing the world's first automobile accident.
History of the Automobile. http://www.misd.org/sci-tech/2000/mhs/120/autohis.htm