Mississippi Democrats legally disfranchised blacks, a demographic and Republican majority, in 1890. They maintained one-party rule by law and terror.

In 1964 Student Nonviolent Coordinating Committee (SNCC), Congress of Racial Equality (CORE), and NAACP activists formed MFDP to register and empower black voters. Its integrated delegation challenged Mississippi's all-white delegates to be seated at the Democratic National Convention in Atlantic City, here refusing a brokered deal for two nonvoting seats. Thus, after exposing the state's racism in the nationally televised testimony of party leader Fannie Lou Hamer, MFDP walked out of the convention. It mobilized locally and statewide back home, increasing voter education, registration, voting, and empowerment.