"Indictment cites bribes, kickbacks related to * WC qualifications in Concacaf; * Gold Cup and Concacaf Champions League * Copa América * Copa Libertadores."
The USA or American owned teams participated in all of those competitions.
The WC qualifiers, Copa América and Gold Cup are international competitions, the USA Men's National Team (as they're called) participates in the WCQ and Gold Cup, although why the Copa América is included is odd, that's a South American competition.
The Copa Libertadores and CONCACAF Champions League are both club competitions, again the Libertadores is odd, that's South American, but 4 clubs from the United States participated in the Champions League (in 2014-15 that was Portland Timbers, Sporting Kansas, New York Red Bulls and DC United)