Four years after its founding, Terminus Legion continues to grow. At a midtown bar several weeks ago, an event called Terminalia drew dozens of fans with black, gold and red scarves, buzzing in anticipation of Atlanta United’s debut. Jorge E. Alonso, the group’s director of brand development, set up two laptops on a table to sign up new members amid the clamor.

Michael Page stood nearby. As he took his wallet from the back pocket of his jeans to pay for a beer, a blue Chelsea F.C. supporter’s card fell to the floor. Page, 49, lived in London for a year three decades ago, an adventurous teenager tending bar at a pub only blocks from Chelsea’s stadium, Stamford Bridge.

A geographer at Emory University, Page is a rarity in Atlanta: someone with family roots here that date back several generations. But he has followed Chelsea and England’s Premier League until now, finding it difficult to warm to M.L.S. because “I didn’t have a team where I’m from.”

A few weeks after Terminalia, Mark Knipfer was nursing his 39-year-old ankles after he and other members of the Faction, another supporters’ group, beat members of Terminus Legion, 2-1, in the last 60 seconds of a Sunday game. The Faction, Knipfer said, is like its founders: half from somewhere else and half native to Georgia, or at least generally Southern. It is more of a family-oriented set, with a website that pledges an embrace of values like “using sport to help develop youth character.”

The Faction raises money to support the Fugees Family, an Atlanta-area program that supports refugee children from 23 countries and that includes a school and soccer team. So far, the money comes from membership fees: $10 for adults, $5 for children. About 100 people have joined, Knipfer said. “We want to get to the point we’re recognized as a formidable force, maybe 1,000,” he said.