Founded in 2008, the Philadelphia Union became Major League Soccer's sixteenth club when they made their debut in the competition in 2010. The franchise was granted to Philadelphia after strong pressure from the MLS supporters group 'Sons of Ben', who managed to convince MLS that there was a strong enough fan base to justify an MLS expansion.
The Union's main rivals are the New York Red Bulls and D.C. United and these two rivalries are based on their relative closeness and sporting rivalries between the cities in other major sports. The team has also developed a rivalry with Seattle Sounders FC, based largely on chance - the Sounders were Philadelphia's first ever MLS opponents and their oppponents for their first match at their current stadium.
The club is still awaiting its first major honour since becoming an MLS franchise. The Union's first season saw them finish 7th in the Eastern Conference and 14th overall in MLS. The 2011 season brought about an improved performance, with Philadelphia finishing 3rd in their conference and 8th overall. The 2012 regular season was slightly less successful, although the team did reach the semi final stage of the U.S. Open Cup.
Some of the more noted players to represent the Union in its history to date include Freddy Adu, Faryd Mondragón, Sébastien Le Toux and the current club captain, Brian Carroll.
The primary stadium used for Philadelphia Union home matches is PPL Park. The ground, which opened in 2010, has a total capacity of 18,500 for Major League Soccer games. In addition, the club occasionally uses Lincoln Financial Field, the home stadium of the Philadelphia Eagles NFL team, for important matches, games with an unusually high demand for tickets and for friendlies against the major overseas clubs. It is capable of holding up to 68,532 fans.