S.C. Code § 3-3-270
The right, title and interest of this State to, and the jurisdiction of this State over, the following described lot or parcel of land has been granted and ceded to the United States for the erection of a public building, to wit: That lot of land in the city of Florence, county of Florence, situate on the northwestern corner of Evans and Irby Streets, fronting on each street one hundred and fifty feet, and known on the plat of the city of Florence, made by J. W. Brunson, surveyor, May 5, 1896, as the eastern part of lot No. 21, in sectional block C, and bounded north by lot No. 20, east by Irby Street, south by Evans Street and west by part of lot No. 21.
There was reserved to this State a concurrent jurisdiction for the execution within said lot of all process, civil or criminal, lawfully issued by the courts of this State and not incompatible with such cession.
S.C. Code § 3-3-270