The earliest known reference to baseball ever recorded in American history dates back to the late18th century in Massachusetts. The first team who played under modern rules - the New York Knickerbockers - dates back to the mid-19th century.
Over time, the sport has of course evolved, but it has been around for quite a while. The sport evolved over time and many people helped mold it to become the sport we know and love.
Many of those people were Italian-Americans.
Fonte: L'italo-Americano