The history of baseball in the United States dates to the 18th century, when boys and amateur enthusiasts played a baseball-like game by their own informal rules using homemade equipment. The popularity of the sport grew and amateur men's ball clubs were formed in the 1830–50s. Semi-professional baseball clubs followed in the 1860s, and the first professional leagues arrived in the post-American Civil War 1870s.

National League Baltimore Orioles, 1896