The baseball is actually quite complicated to manufacture. In the center there is a cork core called the pill. The pill is then wrapped in almost 300 meters of different types of wool. The center piece is then covered in adhesive and two 8 shaped pieces of white tanned leather are then placed on the adhesive. The ball then needs to be hand stitched for more than 10 minutes with a red cotton thread.
Baseballs were originally homemade and baseball was originally only played by milkmaids (women who milked cows). The old baseballs were made of brown leather and also had a solid core. It also wasn't feasible to make them perfectly round.
At one it was part in time, it wasn't against the rules to pelt other players with a baseball (they were however far lighter).
They litteraly rub mud on white balls to give the pitchers more grip and control... (it's even done in major league baseball).
Almost 160,000 baseballs are used per regular season.