Final answer:
CORE and SCLC were central to the success of the sit-in movement, with CORE actively supporting sit-ins and SCLC eventually recognizing the importance of student-led initiatives, leading to the creation of SNCC.
Step-by-step explanation:
The Congress of Racial Equality (CORE) and the Southern Christian Leadership Conference (SCLC) both played instrumental roles in supporting the sit-in movement, which was a pivotal part of the African American civil rights movement. CORE, with its roots in nonviolent civil disobedience and influenced by Mahatma Gandhi, supported student sit-ins at lunch counters across the South to challenge segregation. They were involved in various civil rights actions, including the Freedom Rides of 1961. SCLC, led by figures such as Ella Baker and closely associated with Martin Luther King Jr., was initially cautious about their direct endorsement of sit-ins due to the potential for increased violence against participants. However, SCLC's Ella Baker saw the potential in the student-led movement and facilitated the founding of the Student Non-Violent Coordinating Committee (SNCC), which would become one of the major organizations in the civil rights struggle. CORE and SCLC's efforts, along with those of other civil rights groups, were vital in the push for social change and contributed significantly to the successes of the civil rights movement in the 1960s.