In 1785, the overarching Ninety-Six District was divided into six counties, one of which was to be called "Spartan." Its boundary was Laurens County on the south, the Indian Line of the west, the North Carolina boundary to Broad River, and then down the river to Tate's Ferry, then along the road to John Ford's plantation on the Enoree River. In the original survey Spartan County included one thousand and fifty square miles. However, resurveys reduced it to one thousand and four square miles, and after the forming of Cherokee County in 1897, it was further reduced to seven hundred and sixty-five square miles.

As with many of the very early "new counties" in the state of South Carolina created very soon after the American Revolution, those that were established in 1785 were either later abolished, renamed, or simply fell by the wayside due to inaction by the state in promptly following up with the erection of county court houses and other public buildings. The citizens wanted their local government to be closer than it had been under the "overarching Districts" that had been established in 1769, but many of the citizens also failed to promptly act to pursue their stated goals.

In the case of the newly-defined Spartan County, none of these were really problems. The locals simply wanted to change the name of the district/county to match its also newly-established county seat - which seemed to be "the rage" of that time. Almost all of the newly-created counties after the American Revolution in South Carolina had both new counties and new county seats - both named identically - possibly so the citizens could more-readily accept the "newness" of what was happening to their lives as a result.

In 1791, the state legislature changed the name from Spartan County to Spartanburg County. In 1800, all counties were redesignated as districts. As with the rest of the state, all "districts" were later renamed back to "counties" in 1868.