What kinds of organizations constituted the "infrastructure of black liberation"?
Many different organizations make up, or made up, an infrastructure of black liberation. On the one hand, for almost the entire twentieth century, the NAACP represented causes related to equality for African-Americans, raising money to pursue legal cases related to black equality. It was, for example, the NAACP that organized the legal team that offered the successful challenge to Plessy v. Ferguson in 1954.
Other national organizations took up the effort in the 1960s, including the Congress of Racial Equality (CORE) and the Student Nonviolent Coordinating Committee (SNCC). These organizations helped to coordinate resistance to Jim Crow. As the civil rights movement went on, these organizations became more radical, demanding actual equality for African-Americans, especially economic equality. SNCC, in particular, became part of a "black power" movement that pointed out the many persistent racial problems that remained after legal equality had been achieved in the South. By the early 1970s, these groups had splintered further into black liberation movements such as the Black Panthers and the Black Liberation Army.
It is important to note that these organizations were national in nature, and though they had local chapters, much of the real organization of the black liberation movement was not "top down" but rather the efforts of grass-roots community organizers who worked to elect sympathetic city councilmen, ensure quality schools and police services, and draw attention to other, local concerns. These community organizers often worked out of community centers and businesses, but very often in black churches. In some of these churches, ministers preached a black liberation theology that emphasized social justice and equality as matters of religious faith. Indeed, these institutions remain the single most important agents of organization in African-American communities around the nation.