0 of 26

Trevor Ruszkowski-USA TODAY Sports

The last year in Major League Soccer was one of the most successful periods in the league's history. The 2015 regular season was a massive success and bigger names continued to come over to play in North America.

The 2015 league campaign almost didn't start on time as the owners and players agreed upon on a collective bargaining agreement two days before the first match kicked off.

Once the games began, we witnessed plenty of world-class play from stars like Sebastian Giovinco, David Villa and Kei Kamara. As the season progressed, drama began to build in anticipation of what turned out to be the most exciting postseason in league history.

Off the pitch, the introduction of Targeted Allocation Money was a big storyline as was the midseason transfers of Didier Drogba, Frank Lampard and Andrea Pirlo.

We decided to wrap up the last year in MLS with a complete A to Z guide of the happenings on and off the field during the league's 20th season.