According to baseball historian John Thorn, 1839 is the year Adams became a baseball player. In an 1896 interview in The Sporting News, Adams said that “soon after going to New York I began to play base ball just for exercise, with a number of other young medical men.” Starting in 1840, he was a player with the New York Base Ball Club. This team had been founded in 1837, eight years earlier than the New York Knickerbockers, who are credited in several baseball histories as pioneering the modern version of baseball. Adams played an early form of the game, but Thorn writes that he “understood [it] to be baseball, no matter what it was called”.

Doc Adams, Wikipedia