In which city was ATO's first national headquarters located?

The first national headquarters of the ATO (Alpha Tau Omega) fraternity was located in Champaign, Illinois. This city was significant as it housed the fraternity's founding chapter, which played a crucial role in ATO's early development and organization. Champaign's connection to the fraternity's history makes it the correct answer, as it symbolizes the starting point for the ATO's national expansion. Over the years, ATO has grown and evolved, but its roots in Champaign remain a pivotal part of its identity.