National Guard troops , to assist them .
Crowds of as many as 20,000 overwhelmed the District 's 3,100 - member police force , and President Lyndon B. Johnson dispatched some 13,600 federal troops , including 1,750 federalized D.C.
National Guard troops , to assist troops .
Crowds of as many as 20,000 overwhelmed the District 's 3,100 - member police force , and President Lyndon B. Johnson dispatched some 13,600 federal troops , including 1,750 federalized D.C.