Groupthink is a problem in which group members strive to maintain cohesiveness and minimize conflict by refusing to critically examine ideas, analyse proposals, or test solutions.
It's a sort of uncompromising consensus that can serve only in a former stage of a given plan, or equivalent I think. An example of this, is taking place nowadays in the Venezuelan conflict, where official opposition (Asamblea Nacional; sort of Parliament) are inhibited of criticizing their internal mistakes or approaches to combat Chavismo tyranny, and fail discarding other voices in the opposition that claim to ask for help from the international community, as Maduro and Chavismo represent a criminal state.
The civil rights movement was a social movement with spanned and evolved from the mid-1950s to late 1960s. the movement's goal was to end racial segregation and discrimination against African-American people along with securing Federal citizenship rights.