How did students at a lunch counter and riders on a bus force a federal response?

The sit-ins and the Freedom Rides forced a federal response because they showed, in public and at some personal risk, that segregation was still happening in places where the law already said it should not, and that Southern officials would not stop it. On 1 February 1960, four freshmen from North Carolina A&T, inspired by King's practice of nonviolent protest, sat down at the lunch counter of a Woolworth store in Greensboro. They had bought toothpaste and other items elsewhere in the store without trouble, but were refused service at the counter. They stayed until the store closed, then went back to campus and recruited more students for the next morning.

The idea spread fast. The sit-in movement involved some 70,000 people, and it contributed to the formation of the Student Nonviolent Coordinating Committee. Students also boycotted stores with segregated lunch counters, and sales dropped by a third, leading owners to abandon segregation policies. The Greensboro sit-ins led Woolworth to remove its segregation policy across the South.

In 1961 came the Freedom Riders. The Supreme Court had ruled that segregated interstate buses were unconstitutional, but the Southern states ignored the rulings and the federal government had done nothing to enforce them. The riders, in mixed racial groups, rode interstate buses into the South to test that. On 14 May in Anniston, Alabama, a mob of Klansmen attacked the first bus, and threw a firebomb into it. In Birmingham, a mob attacked the riders, aided and abetted by police.

Federal pressure came after that. When the Kennedys asked for a cooling off period, CORE's James Farmer answered that Black Americans had been cooling off for 350 years. New rules from the Interstate Commerce Commission took effect on 1 November 1961, and the "white" and "colored" signs came down in bus and rail terminals.