MLS expansion boom continues at unprecedented rate in modern sports

And then there were 29. Soon, there will be 30. Major League Soccer continues to grow at a staggering rate for modern sports leagues.

Sacramento was awarded team No. 29, becoming the latest city to win an MLS expansion team after years of trying. As a result, the league's continental footprint continues to grow, adding a fourth club in California in a city that has long hoped to make the jump.

In 2009, MLS was made up of 15 teams. It has nearly doubled in size in a decade. 

MLS Expansion

Here's a timeline of the latest expansion clubs which have joined the league beginning in 2010: 

  • 2010 (16 teams): Philadelphia Union
  • 2011 (18 teams): Portland Timbers, Vancouver Whitecaps
  • 2012 (19 teams): Montreal Impact
  • 2015 (20 teams): NYCFC, Orlando City
  • 2017 (22 teams): Atlanta United, Minnesota United
  • 2018 (23 teams): LAFC 
  • 2019 (24 teams): FC Cincinnati
  • 2020 (26 teams): Inter Miami CF, Nashville SC
  • 2021 (27 teams): Austin FC
  • 2022 (29 teams): St. Louis, Sacramento

Expansion in other pro leagues

So how does MLS expansion compare to what has occurred in other professional team sports? 

Major League Baseball (MLB):

Between 1961 and 1969, MLB added nine teams. But in the 50 years since 1969, baseball has grown by just six more teams, including most recently in 1998, to bring their grand total to 30 teams.

National Basketball Association (NBA):

Since four teams joined as part of the 1976 NBA-ABA merger, the league has added just eight new franchises. The New Orleans Pelicans were the most recent expansion side to join back in 2002, becoming the league’s 30th team. 

National Football League (NFL):

Like the NBA, the NFL had a wave of teams added in a merger with another league, officially merging with the AFL in 1970. Ten teams were added that season and the league has grown by just six more teams since 1970 to take their total to 32.

National Hockey League (NHL):

Building on the "original six" from 1942-43, the NHL’s expansion began in earnest in 1967 when they doubled in size to become a 12-team league, though one of those teams is defunct today. After adding 10 more teams in the 1970s to take their total to 21 teams, the NHL has added another 11 franchises. Behind MLS, the NHL has experienced the most recent expansion among major pro sports leagues, with the Las Vegas Golden Knights becoming the 31st franchise in 2017. They will add a 32nd, Seattle, in 2021.