Final answer:
The protest first seen at a Greensboro, North Carolina lunch counter in 1960, which involved four students and lasted six months, was a sit-in, marking a key moment in the African American civil rights movement.
Step-by-step explanation:
The kind of protest that first appeared at a Greensboro lunch counter in 1960 by four students and lasted six months is known as a sit-in. On February 1, 1960, Ezell Blair, Jr., Joseph McNeil, David Richmond, and Franklin McCain, also known as the "Greensboro Four," initiated this form of nonviolent protest to challenge segregation at the Woolworth's lunch counter. Despite being refused service and faced with hostility, they remained seated, inspiring many others to join what came to be known as the Greensboro Sit-Ins. This was a significant act that helped ignite the student phase of the African American civil rights movement, leading to the creation of the Student Non-Violent Coordinating Committee (SNCC).