12 times the president called in the military domestically:
1957-58 Desegregation of Little Rock school
1962 Integration of University of Mississippi
1963 Integration of University of Alabama
1963 Integration of Alabama schools
1965 Selma, Montgomery civil rights march
1967 Detroit riots
1968 Chicago riots following assassination of Martin Luther King Jr.
1968 Washington riots following King's murder
1968 Baltimore riots following King's murder
1970 New York City postal strike
1989 Looting after Hurricane Hugo
1992 Riots after Rodney King verdict

Source: http://www.chicagotribune.com/news/ct-national-guard-deployments-timeline-htmlstory.html