A civil rights activist is a leader of the political movement dedicated to securing equal opportunity for members of minority groups. The civil rights movement was a nonviolent social movement and campaign from 1954 to 1968 in the United States to abolish legalized racial segregation, discrimination, and disenfranchisement in the country. The movement had its origins in the Reconstruction era during the late 19th century and had its modern roots in the 1940s, although the movement made its largest legislative gains in the 1960s after years of direct actions and grassroots protests. Civil rights activists worked together and used non-violent protest and specific acts of targeted civil disobedience, such as the Montgomery Bus Boycott and the Greensboro Woolworth Sit-Ins, in order to bring about change. Some of the most well-known civil rights activists include Rosa Parks, Martin Luther King Jr., and Thurgood Marshall.