The Insurrection Act

Building on earlier militia laws of 1792 and 1795, Congress passed the Insurrection Act on March 3, 1807, allowing the President to use the regular Army and Navy, not just the militia, to suppress insurrections and enforce federal law. Its provisions, now found at 10 U.S.C. 251 to 255, let the President use the armed forces and federalize the National Guard when a state asks for help against an insurrection, when unlawful obstructions make it impracticable to enforce federal law by ordinary means, or when violence deprives people of constitutional rights and state authorities cannot or will not protect them.

Before using troops, the President must issue a proclamation ordering the insurgents to disperse. Presidents have invoked the law about 30 times, including during the Whiskey Rebellion era, labor strikes in the late nineteenth century, and the civil rights era, when President Dwight Eisenhower sent the 101st Airborne to enforce school desegregation in Little Rock in September 1957 and President John Kennedy sent troops to the University of Mississippi in 1962 and to Alabama in 1963, over the objections of governors. The most recent invocation came in May 1992, when California's governor requested troops during the Los Angeles riots.

The law gives the President broad discretion and has few procedural limits, and courts have generally been reluctant to second-guess an invocation. Its use was discussed during the 2020 protests and, repeatedly, in 2025, when the President said he might invoke it to support immigration enforcement and deployments to cities, though he relied instead on other authorities to federalize Guard troops. Supporters say the law is a necessary tool to restore order and enforce federal court orders, while critics, including scholars across the spectrum, say its vague terms invite abuse and have proposed reforms requiring congressional approval for extended deployments.