The influential politician known for their role in the American Civil Rights movement is Martin Luther King Jr.. As a prominent leader, King advocated for nonviolent protest and civil disobedience to combat racial segregation and injustice. His leadership in events such as the Montgomery Bus Boycott and the March on Washington were pivotal in raising awareness and mobilizing supporters for civil rights legislation. King's legacy established him as a symbol of the struggle for racial equality and social justice, inspiring movements worldwide.