Why Drive on the Left?

The practice is believed to date back to ancient Rome. Romans steered their carts and chariots with the left hand, to free up the right so they could use weapons to defend against enemy attacks. This carried over into medieval Europe and in 1773, the British government passed measures to make left-hand traffic the law.

Why do Americans drive on the right?

Drivers tended to sit on the right so they could ensure their buggy, wagon, or other vehicle didn't run into a roadside ditch. ... Thus, most American cars produced before 1910 were made with right-side driver seating, although intended for right-side driving.

Why Driving on the left is better?

Most people are right-handed, so by driving on the left, that'd place their stronger hand in the best position to greet those coming the other way, or whack them with a sword, as seemed most appropriate. ... Most people find it easier to mount a horse from its left, too.