Document that statement.
Walt
Moultrie, Johnson, and Pinckney were given to federal control in 1805. The process by which they were obtained under federal control was a 1794 statute in which the government was authorized to recieve cessions of land from the states. That statute signified that cession was conditional to the terms of a given state:
See http://memory.loc.gov/ll/llsl/001/0400/04700346.gif
In the 1805 act, South Carolina imposed conditions upon its cession of the land, those being that the US had to occupy and maintain the forts within three years of the act.
"That, if the United States shall not, within three years from the passing of this act, and notification thereof by the Governor of this State to the Executive of the United States, repair the fortifications now existing thereon or build such other forts or fortifications as may be deemed most expedient by the Executive of the United States on the same, and keep a garrison or garrisons therein; in such case this grant or cession shall be void and of no effect."