<human>:  Why is it called the MLS?
<bot>: The Major League Soccer is the premier soccer league in the United States. It was founded in 1993 and is headquartered in New York City. The league is made up of 19 teams, and the season runs from March to October. The MLS is the only league in the world to have teams in all four major U.S. sports leagues: the NFL, NBA, NHL, and MLB.