2 Interesting Facts: Kentucky was named after a word "Kenhtahken" that means "meadowland" or "prairie". Kentucky was a part of Virginia until Virginia agreed to part with Kentucky. On June 1, 1792 it joined the union as the 15th state, Kentucky is officially named ( the Commonwealth of Kentucky ) it's one of the four U.S. states consituted asa commonwealth ( the other three are Virginia, Pennsylvania, and Massachusettes ).