Oklahoma, state in the southern United States; 181,048 km2, 3.75 million population (2010), of which 72% white, 8% Native American and 7% black. The capital and largest city is Oklahoma City. Joined the Union in 1907 as the 46th State; nickname: The Sooner State. COUNTRYAAH.COM: Lists all counties and parishes of Oklahoma in alphabetical order. […]