Oklahoma () is a state that is in the southern part of the Central United States. It had a population of about 3,751,351 people in 2010. The state has a land area of about . Oklahoma is the 28th largest state by population and the 20th largest state by area. The name of the state comes from the Choctaw words "okla" and "humma". It means "Red People". It is also known by its nickname, "The Sooner State." The state was formed from Indian Territory on November 16, 1907. It was the 46th state to become part of the United States. The people who live in the state are known as "Oklahomans" or "Okies". The state's capital and largest city is Oklahoma City.