Okmulgee While the county was founded at statehood in 1907, the birth of the city of Okmulgee occurred years earlier, following the U.S. Civil War in 1868. Then known as Okmulke, it wasn’t until 1883 that it got the spelling we know today. The town, which is the Capital of the Muscogee (Creek) Nation, was also the governmental seat of what would soon become Oklahoma.