President Lyndon B. Johnson activated the National Guard and deployed federal troops to multiple cities, including Washington, D.C., Baltimore, and Chicago, in April 1968 following the assassination of Martin Luther King Jr., which sparked widespread riots.

He also federalized the Michigan National Guard and sent U.S. Army paratroopers to Detroit in 1967 to quell a major urban uprising.

https://brendonbeebe.substack.com/p/when-presidents-sent-the-national