43 U.S. Code § 774 - Protection of surveyor by marshal
Whenever the President is satisfied that forcible opposition has been offered, or is likely to be offered, to any surveyor or deputy surveyor in the discharge of his duties in surveying the public lands, it may be lawful for the President to order the marshal of the State or district, by himself or deputy, to attend such surveyor or deputy surveyor with sufficient force to protect such officer in the execution of his duty, and to remove force should any be offered.
Source(R.S. § 2413.)
R.S. § 2413 derived from act May 29, 1830, ch. 163, § 2,4 Stat. 417.