Federalizing the National Guard: A brief history

President Trump announced this week the deployment of 800 members of the D.C. National Guard to the District of Columbia, as part of a push to crack down on crime in the nation's capital. The president is also temporarily taking control of the District's Metropolitan Police Department. Hundreds of additional federal law enforcement officers have also joined the effort recently, from a variety of agencies fanning out across the city.

"I'm deploying the National Guard to help reestablish law, order and public safety in D.C., and they're going to be allowed to do their job properly," Trump said at a White House news conference Monday.

The Army activated the D.C. National Guard to "assist law enforcement in the nation's capital," it said in a statement, and added that, of the approximately 800 soldiers activated, 100 to 200 would be supporting law enforcement at any given time on an "array of tasks from administrative, logistics and physical presence." The Guard week was activated under Title 32, which concerns the role of the Guard when it is under the control of its state's governor, or in this case, the president. D.C. Guard members have the authority to make arrests while they're in this status, but defense officials say that for now, the mission is focused on supporting law enforcement. 

Here's what to know about the history of presidents federalizing the National Guard for the purpose of peacekeeping and law enforcement:

According to the National Guard website, throughout U.S. history, presidents have federalized state militias and the National Guard to conduct or support a wide range of civil disturbance operations.

• In 1792, Congress first authorized the President to call forth the militia in order to repel invasions, suppress domestic insurrections, and enforce federal laws. Since then, other key statutes including the Militia Acts of 1795, 1862, 1903, the Insurrection Act of 1807, and Title 10 of U.S. Code, have redefined or expanded the militia and National Guard's roles in civil disturbance operations under federal authority.

• In 1794 and 1799, Presidents George Washington and John Adams called upon state militia and volunteer units to suppress the Whiskey Insurrection and Fries' Rebellion.

• For most of the 19th century, presidents avoided calling upon the militia in response to civil disturbances. Instead, state militias quelled labor riots and slave revolts, only coordinating with federal officials or units when available.

• The great exception of the 19th century occurred during the Civil War and Reconstruction. In April 1861, President Abraham Lincoln called up a militia force of 75,000 men to suppress the southern slaveholders' rebellion, known as the Confederacy. Throughout the war and Reconstruction, federalized militia units played critical roles in civil disturbance operations, defending America's "new birth of freedom," and protecting the expansion of democracy and citizenship.

• State militias and the new, modern National Guard played active roles in quelling the race riots and labor strikes throughout the late 19th and early 20th centuries. However, between 1867 and 1957, no president federalized the militia to conduct or support civil disturbance operations.

• Throughout the Civil Rights era, Presidents Eisenhower, Kennedy, and Johnson federalized the National Guard under Title 10 U.S. Code to enforce the expansion of civil rights and to ensure public order. Notable incidents include the desegregation of Central High School in Little Rock in 1957, the University of Mississippi in 1962, the University of Alabama and Alabama public schools in 1963. The Alabama National Guard was also called into federal service for the Selma-Montgomery March in 1965.

• Beginning with the Detroit Riots in 1967, presidents federalized the National Guard to support law enforcement agencies in response to civil unrest. The King Assassination Riots in 1968, the New York Postal Strike in 1970, and the Los Angeles Riots in 1992 were the last incidents in which a president federalized the National Guard for civil disturbance operations.

• President Trump federalized the California National Guard earlier this year, against the wishes of Governor Gavin Newsom, to support local law enforcement efforts to contain civil unrest in Los Angeles in response to the administration's immigration crackdown.