Fans in Boston have spent more than two years building a supporters' culture for the city's new NWSL franchise, the Legacy, forming the Independent Supporters' Association (ISA) before the club even had a name, mascot or roster. Their efforts culminated in a striking display at the team's home opener at Gillette Stadium in March 2026, reflecting the depth of grassroots organisation behind a franchise that arrived nearly a decade after Boston last had a professional women's soccer team.

The ISA formed shortly after the NWSL announced Boston as an expansion city in September 2023, and members networked with club founders and ownership long before the team's identity was confirmed. At the season-opening match on 14 March 2026, ISA members marched in behind a school marching band, displayed "Up the Swans" scarves and unveiled a hand-painted tifo reading "Our Legacy Takes Flight" in front of a crowd of more than 30,000 inside the nearly 65,000-capacity stadium. The Legacy are playing their debut season without a permanent home, alternating between Gillette Stadium in Foxborough, Massachusetts, and Centreville Bank Stadium in Pawtucket, Rhode Island, while White Stadium in Boston is built, with completion expected by 2028; the effort follows the sudden 2017 folding of the previous Boston Breakers franchise, a loss still felt by local fans.