Tulsa ( /tʌlsə/) is the second-largest city in the state of Oklahoma and 46th-largest city in the United States. With a population of 391,906 as of the 2010 census, it is the principal municipality of the Tulsa Metropolitan Area, a region with 937,478 (2010) residents in the MSA and 988,454 (2010) in the CSA. Tulsa's CSA is projected to reach one million between 2010 and 2012. The city serves as the county seat of Tulsa County, the most densely populated county in Oklahoma, and extends into Osage, Rogers, and Wagoner counties.
Tulsa was first settled between 1828 and 1836 after the attack by the Lochapoka Band of Creek Native American tribe. In 1921, it was the site of the infamous Tulsa Race Riot, one of the largest and most destructive acts of racial violence in the history of the United States. For most of the 20th century, the city held the nickname "Oil Capital of the World" and played a major role as one of the most important hubs for the American oil industry. Tulsa, along with several other cities, claims to be the birthplace of U.S. Route 66 and is also known for its Western Swing music.
Once heavily dependent on the oil industry, economic downturn and subsequent diversification efforts created an economic base in the energy, finance, aviation, telecommunications and technology sectors. The Tulsa Port of Catoosa, at the head of the McClellan-Kerr Arkansas River Navigation System, is the most inland river port in the U.S. with access to international waterways. Two institutions of higher education within the city operate at the NCAA Division I level, Oral Roberts University and the University of Tulsa.