There has been some debate about the origins of modern soccer in America. It has long been held that the modern game entered the States through Ellis Island in the 1860s. However, recent research has shown that soccer entered America through the port of New Orleans, as Irish, English, Scottish, and German immigrants brought the game with them. It was in New Orleans that many of the first games of soccer in America were played.
Boston's very own Oneida Football Club has been named as the first association football club in the United States but there is still discussion on what rules the club used, and it broke up within the space of a few years. According to Encyclopedia Britannica, the club is often credited with inventing the "Boston Game", which both allowed players to kick a round ball along the ground, and to pick it up and run with it.
Here's a photograph of a monument commemorating the Oneida Football Club located in Boston Common and it bears the following inscription:
This monument is placed on Boston Common November 1925 by the seven surviving members of the Team