Rooted in race and class struggles for equality, including workers’ right to organize, from the 1930s–40s, the modern CRM emerged 1955–68 and subsided ca. 1976. Black-led and southern based, it drew on black communities, especially churches, schools, colleges, and civic and social organizations, along with multiracial coalitions and federal action.

As the United States mobilized and entered World War II, officially to defeat fascism and save democracy, blacks attacked Jim Crow. Black newspapers began a “Double V” campaign, “victory over our enemies at home and victory over our enemies on the battlefields abroad.” Blacks planned a mass march on Washington to protest job discrimination in defense industries, but canceled it when the president established a committee on fair employment. Southern black leaders “fundamentally opposed” segregation in their Durham, North Carolina manifesto, challenging liberal white southerners to cooperate. More than 100 race riots and many “sit down” protests at white-only restaurants (later called sit-ins) occurred nationally. Sit-downs attested to the impact of direct action and NAACP “equal protection” lawsuits. One, Smith v. Allwright(1944), resulted in the Supreme Court outlawing the white primary, a major obstacle to black suffrage.

Racial injustice still gripped postwar society, which embarrassed the United States in the Cold War against Communism. Amid the “Red Scare” and persecution of communists, such as the Civil Rights Congress, the battle to abolish “separate but equal” continued. Circa 1943–53 alone blacks undertook eighteen school boycotts and strikes, ten of them in border and southern states. A Farmville, Virginia high school student strike generated one of the NAACP suits contesting segregated schools. Black citizens of Baton Rouge, Louisiana boycotted buses. These enlarging battles catalyzed the president's 1948 order integrating the US Armed Forces and the 1954 Brown decision ending separate schooling.

Post-Brown, the movement determined to desegregate the South while securing equal citizenship and opportunities for all Americans. Despite “massive resistance,” which involved legal subterfuge, intimidation, and sometimes murder, the movement's leadership and followers advocated nonviolence. However, North Carolina NAACP branch president Robert Williams and his members armed to repel the Ku Klux Klan in 1958–59; the National Office expelled him. Activists mainly pursued desegregation of education, public accommodations, employment, and politics, using school transfer petitions, bus boycotts, pickets, sit-ins, Freedom Rides, voter registration, a March on Washington for Jobs and Justice, and Freedom Schools.