There is a pretty interesting random questions thread from years ago, if you’re looking for that type of thing.
Popa as usual only gives made up answers. The term Uncle Sam was from a confusion between a food supplier for the army and the US stamped on the barrels.
The reason we drive on the left is to do the opposite of our sponsor nation UK. I’m not sure if there is a reason why they picked the left side of the road, but they had to pick one! We then did the other one.
Congress legislates DST for the US. Some exceptions are allowed. Other countries can make their own rules for themselves. The question of leap seconds is much more.interesting, because it has to be accepted internationally.