Short answers, pulled from the story.
The largest crowd in NFL history was 112,376 fans, recorded at the American Bowl on the 15th of August 1994 at Estadio Azteca in Mexico City. The game was the Governor's Cup between the Dallas Cowboys and the Houston Oilers.
The American Bowl ran from 1986 to 2005. The first game was played on the 3rd of August 1986 at Wembley Stadium in London, and the last was held in 2005 at the Tokyo Dome.
American Bowl games were held in London, Tokyo, Berlin, Montreal, Barcelona, Mexico City, Monterrey, Dublin, Toronto, Vancouver, Sydney, and Osaka, among other cities. Wembley Stadium in London and the Tokyo Dome in Japan were the most frequent venues.
After Roger Goodell became NFL commissioner in 2006, the league shifted from international preseason games to regular season games abroad. NFL Europa was also shut down after its 2007 season as part of this strategic change.
The Dallas Cowboys appeared in nine American Bowl games, more than any other franchise. They won only one of those contests.
The NFL International Series replaced the American Bowl format, beginning with a regular season game at Wembley Stadium on the 28th of October 2007, when the New York Giants beat the Miami Dolphins 13-10. That was the first regular season NFL game played outside North America.