43 U.S.C. § 986

All land selected and reported to the General Land Office as swamp and overflowed land by the several States entitled to the provisions of said Act of September 28, 1850, prior to March 3, A.D. 1857, are confirmed to said States respectively so far as the same remained vacant and unappropriated and not interfered with by an actual settlement under any law of the United States.