Ten years before 2015, the NFL began a step towards becoming more of an international football league, playing a regular season game in another country for the first time with a 2005 game in Mexico City. Starting in 2007, the NFL played at least one regular game each year at Wembley Stadium in London.
The IFL, the Spacers and the Bears are mentioned only in the novelization of Part II in a description of one of the programs that Marty Jr. is watching on his video glasses. In the movie, Marty Jr.'s exclamation "Fumble!", while wearing the glasses at dinner, suggests that he is watching a football game of some sort.