Philadelphia goalkeeper and Ridley Park, Pennsylvania native Bob Rigby became the first soccer player to be featured on the cover of Sports Illustrated following the club's championship.

The centerpiece of their efforts was a $31 million soccer-specific stadium to be built across the street from the CURE Insurance Arena and with access to the under-construction NJ Transit River Line.

[7] Ultimately, $100 million in state bonds to fund the stadium and various other improvements on the Rowan campus were dropped by New Jersey Governor Jon Corzine.

Shortly after the Rowan proposal fell through, Keystone Sports & Entertainment (the group that would eventually own the Union) looked at a site underneath the Commodore Barry Bridge in Chester to develop a soccer-specific stadium.

[9] The finalization of the club was the result of a $47 million package approved by Delaware County politicians and Pennsylvania governor Ed Rendell that included the cost of Subaru Park and a major urban renewal project.

[15] Sébastien Le Toux became the first player to score a goal for Philadelphia in their home opener on April 10, 2010, a 3–2 win over D.C. United at Lincoln Financial Field.

The team made a complete turnaround in the 2011 season, finishing 3rd in the Eastern Conference and 8th overall in the league with a record of 11–8–15 (W-L-T) scoring 44 goals and allowing 36.

The Union finished their third season in eighth place in the Eastern Conference and fifteenth in MLS overall, with a record of 10–18–6 (W-L-T), scoring 37 goals and allowing 45.

On April 20, 2014, the Union traded forward Jack McInerney to the Montreal Impact for winger Andrew Wenger, a Lancaster, Pennsylvania native.

Although failing to make the playoffs, the Union reached the 2014 Lamar Hunt U.S. Open Cup finals for the first time in the club's history.

During the 2015 MLS SuperDraft the Union drafted forward Dzenan Catic from Bosnia-Herzegovina, midfielder Eric Bird, and defender Raymond Lee.

During the 2015 summer transfer window, the Union traded longtime defender Sheanon Williams to the Houston Dynamo for allocation money, which they used to sign Swiss midfielder Tranquillo Barnetta on July 29, 2015.

Despite disruptions from the COVID-19 pandemic, the Union reached the semi-final of the MLS is Back Tournament and went on to win their first trophy finishing top of the league standings and earning the 2020 Supporters' Shield.

[25] Within two days prior to the Union's first ever conference final match in team history, it was reported that 11 players, including six starters had to undergo the league's COVID-19 protocol.

The overall season proved to be special, as Philadelphia topped the Eastern table with 67 points—equal with Supporters' Shield winners Los Angeles FC (and with better goal differential but lost out due to MLS' tiebreaker of total wins).

In MLS Cup, the Union erased 1−0 and 2−1 deficits and center back Jack Elliott scored twice in the match, including late in extra time.

The rattlesnake pays homage to the "Join, or Die" political cartoon by Benjamin Franklin that was featured in the 1754 Pennsylvania Gazette, and is also reminiscent of the Gadsden flag, another Revolutionary icon.

Subaru Park's design allows clear views of the Delaware River for approximately sixty percent of its spectators, and is the centerpiece of Chester's urban renewal process.

[44] In addition to Subaru Park, the Union also plays select games at Lincoln Financial Field, the home stadium of the NFL's Philadelphia Eagles and the NCAA's Temple University Owls football team.

Prior to the completion of the then PPL Park, the Union played their home opener at Lincoln Financial Field on April 10, 2010, against D.C. United as well as their May 15 match against FC Dallas.

Lincoln Financial Field remains the team's secondary home, for matches with anticipated high attendances, such as a friendly against Manchester United, during their 2010 tour of North America.

[47] Lincoln Financial Field also hosts international friendlies involving teams other than the Union; the most recent being Real Madrid against the Scottish Premier League's Celtic F.C.

The school is located at the Union's training complex in Chester, Pennsylvania and is designed for student-athletes who aspire to play professional-level soccer.

The Sons of Ben petitioned Major League Soccer to expand to the Philadelphia market until the official expansion announcement was made in January 2008.

[78] The various supporters groups collaborate on match day activities, charity initiatives, and the annual 'Help Kick Hunger' fundraiser, which has raised over $100,000 for Chester community food programs since its inception.

These rivalries exist primarily because of geographical proximity and the traditional animosities between the metropolitan areas of Philadelphia and New York City in other professional sports leagues.

[80][81][82] Though early fixtures between the two clubs did spark tensions between the two sets of fans, the rivalry reached a new level after New York City controversially eliminated the Union in the 2021 Eastern Conference Final, after the latter lost 11 players, including six starters, due to MLS's COVID-19 protocols.

Other teams such as the New England Revolution and Atlanta United FC have been considered rivals to some extent due to many intense and important games against them, and some controversial moments.

Until the 2022 season, WPHL-TV and WPVI-TV were the main English-language television broadcasters for Union matches not carried by Major League Soccer's national media partners, with JP Dellacamera on play-by-play.

Jay Sugarman, (CEO) of iStar Financial, leads this group including Christopher F. Buccini, Robert Buccini, and David B. Pollin – co-founders of the Buccini/Pollin Group; Joseph J. Greco, chairman of the RevSpring technology company and president of Premier Management Services; and David Seltzer, principal and co-founder of the Mercator financial advisors.