Mulligan operated professional boxing clubs in Hartford and Waterbury, Connecticut.

The final bout occurred in 1926 in Hartford between Kaplan and Bobby Garcia for the featherweight title.

[1] In 1925, Mulligan signed Harry Stuhldreher of Notre Dame's Four Horsemen as the first national star to ever play pro football in Connecticut.

However, after the Blues' 1926 season, the NFL's owners voted to streamline the league and cut back from 22 to 12 teams.

Red Grange's New York Yankees, from the first American Football League were also to be included as one of the 12 teams.