Who worked primarily for civil rights and equality in the United States?

The choice of Martin Luther King Jr. is accurate because he is widely recognized as a leading figure in the American civil rights movement. His commitment to nonviolent protest against racial segregation and discrimination played a pivotal role in advancing civil rights for African Americans in the 1950s and 1960s. King’s speeches, most notably "I Have a Dream," articulated a vision of racial equality and justice, inspiring countless individuals and mobilizing a nationwide movement for civil rights.

While Malcolm X, Abraham Lincoln, and Rosa Parks all made significant contributions to the civil rights struggle, King’s approach and impact during the movement uniquely positioned him as a central figure in the fight for equality. Malcolm X focused primarily on more militant approaches to civil rights, which differed from King's philosophy of nonviolence. Abraham Lincoln, though important for the emancipation of enslaved individuals, operated in a different historical context concerning civil rights. Rosa Parks is celebrated for her pivotal act of defiance that sparked the Montgomery Bus Boycott and was an essential contributor to civil rights, but she did not have the same level of nationwide leadership and influence as King. Hence, Martin Luther King Jr. is recognized as a primary leader for civil rights and equality in the United States.