When Major League Soccer announced a partnership with the United Soccer League in 2013, it was seen as a large boost for the lower division league. Within the U.S. lower divisions, the USL had struggled to stand apart from the higher-spending NASL. This pact with the top flight helped the league get its first shorthand descriptor: a developmental league for up-and-coming domestic players.



Over the ensuing six years, the USL has built a stronger independent identity. Overwhelming successes in what once appeared to be risky soccer markets has helped carve a vast footprint for the USL Championship and a growing cartography for League One. The league has helped develop plenty of solid pros, too. The list of recent players who parlayed time in the USL into top-flight success includes Tyler Adams, Aaron Long, and Mark-Anthony Kaye — a U.S. men’s national team lynchpin, an MLS Defender of the Year, and an All-Star from MLS’s best team.



The markets...