This chapter argues that cooperation and relative unity among US soccer fans are the result of the specific history, geography and politics of professional soccer in the country, based on ethnographic participant observation and qualitative interviews with organised soccer supporters in New York City. Soccer has been growing as a spectator sport in the US, and a supporters' subculture has emerged in the past two decades. Compared to leagues around the world, current professional soccer leagues in the US have a relatively short history. The predominance of cooperative relations between soccer supporters in the US as well as the emerging importance of antagonism in some local contexts equally point to the significance of subcultural identities and their salience. Major sources of cooperation among soccer fans in the US are the sense of belonging to a unified community of soccer fans taking precedence over team allegiance and the belief that 'growing the game' constitutes a shared goal among all soccer fans.