The civil rights movement escalated from nonviolent to more radical protest because some activists felt that progress was too slow.

The statement is true. The Civil Rights Movement escalated from nonviolent to more radical protest because some activists felt that progress was too slow.  

Explanation:

The Civil Rights Movement was a movement that appeared in the southern states of the United States of America between 1955 and 1968, with the aim of prohibiting racial discrimination against African Americans and reestablish their voting right through nonviolent methods.

From the mid-1960s, however, the civil rights movement disintegrated. With violence against civil rights activists increasing, sympathy for leaders like Malcolm X, a prominent protagonist of the Black Muslim movement, grew among the movement's young radicals. In 1966, under its new, controversial chairman, Stokely Carmichael, the SNCC swore off the non-violent resistance and renounced the civil rights movement. Instead, he called for Black Power.

In their violent form, black power and black nationalism were also expressed in the Black Panther Party. This legitimized its militancy with the still existing racist violence against blacks in the USA.