In 1957, President Eisenhower took control of the Arkansas National Guard away from Gov. Faubus, who used it to stop integration of Little Rock Central High School. He also sent Army paratroopers to escort students and stop protests against them.

Parents of the Little Rock Nine, the Black students who entered high school amid angry mobs, sent a telegram to Eisenhower later, saying his actions had strengthened their faith in democracy.

In 1963, Governor George Wallace blocked the door of the University of Alabama so that two Black students could not attend. To enforce desegregation, President Kennedy federalized all 17,000 of Alabama’s National Guardsmen – something he said he did reluctantly.

In 1965, President Johnson (above) used his power to protect the legendary Selma, Ala., voting rights march from counter protesters and white vigilantes. In a remarkable moment, Johnson took on Gov. Wallace, a fellow Southerner.

But in 1968, at the request of local officials, Johnson did deploy federal troops to quell protests and disturbances n several cities after the assassination of the Rev. Martin Luther King Jr.

The most recent use of the Insurrection Act was in 1992, when President George H.W. Bush sent troops to California during the violence after Rodney King’s beating, after an appeal by the Republican governor, Pete Wilson.

On Wednesday, Defense Secretary Mark Esper distanced himself from President Trump, saying use of active duty troops should be a “last resort” only for “urgent and dire” situations. “We are not in one of those situations now. I do not support invoking the Insurrection Act.”

Calling the move both “illegal” and “authoritarian,” some states have vowed to go to court if Trump tries to deploy troops without their permission. The Pentagon has already moved troops from Fort Bragg and elsewhere to locations near Washington, despite its mayor’s opposition, to be ready if needed.

Kirk Cohall, a CUNY Newmark J-Corps intern, and reporter Noah Madoff contributed research. Learn something new from history: Subscribe to our newsletter, and follow us on Twitter @RetroReport.