The largest non-merger conference expansion in NCAA history occurred on December 9, 1993 when Cleveland State, UIC, Northern Illinois, Wisconsin-Green Bay, Wisconsin-Milwaukee, and Wright State left the Mid-Continent to join the Midwestern Collegiate beginning with the 1994–95 academic year. With Evansville's departure to the Missouri Valley Conference, there were 12 league members. Xavier, Notre Dame, and La Salle withdrew the following summer of 1995, followed by Northern Illinois in 1997. The conference changed its name to the Horizon League on June 4, 2001, in part due to the initials causing confusion between the MCC and the Mid-Continent Conference (who also used the initials). That year, Youngstown State University came to the Horizon League from the Mid-Con, and on May 17, 2006, Valparaiso University announced it would do the same in 2007. As of the 2020–21 school year, nine of the 12 Horizon League members are former members of the Mid-Con (now known as The Summit League), with the exceptions being Detroit Mercy, Northern Kentucky, and Robert Morris. In addition, four former members are currently in the Atlantic 10 Conference, and three former members are in the current Big East Conference.