Roulette wheels used to be numbered 1 to 36, but in 1842, Frenchmen François and Louis Blanc added the "0" to the roulette wheel in order to achieve a house advantage.
(And it gets worse, in the early 1800s, roulette was brought into the U.S. where, to further increase house odds, a second zero, "00", was introduced. So you see, the house always wins.)