Left-side driving

Why do Americans drive on the right and in the UK they drive on the left?

Jazzy wrote:

Why do Americans drive on the right and in the UK they drive on the left?

That is probably an unanswerable question.

Sometime ago I had asked myself this same question. My research led me to accept certain statements and satisfy me with the answers.

France and Spain colonized a large part of the "New World" and they drove their carriages on the right sitting on the left and leaving their right hand free for the whip. They could better judge the distance when other carts were passing. By this time the sword was being replaced by firearms for protection. In the UK it was actually a holdover from the time that carts were not as popular and when walking they would walk on the left to keep their sword hand free for protection.

There are more countries that drive on the right and it's a commerce thing now. It makes it easier for transportation when everyone using the right side of the road.

Sweden changing lanes.