The following outline is provided as an overview of and topical guide to the United States Commonwealth of Kentucky: Kentucky – state located in the East Central United States of America, nicknamed the "Bluegrass State", due to the presence of bluegrass in many of the pastures throughout the state. As classified by the United States Census Bureau, Kentucky is a Southern state, in the East South Central region. Kentucky is the 37th largest state in terms of total area, the 36th largest in land area, and ranks 26th in population. Originally a part of Virginia, in 1792 it became the 15th state to join the Union. Kentucky is designated a commonwealth by the Kentucky Constitution and is known as the "Commonwealth of Kentucky."