premise: Hill College is a comprehensive community college located in Hillsboro, Cleburne, Burleson, Glen Rose and Meridian, Texas. Hill College opened its doors in 1923, one year before North Central Texas College, which is the oldest continuously-operating community college in Texas because Hill College was closed during the 1950s.
hypothesis:  several colleges opened its doors in 1923
reason: we only know of one college opening its doors in 1923; there could be more or there could not be. I think the system recognized that hill college had multiple campuses and assumed these all opened at the same time.