Rosa Parks was important because in December of 1955, her refusal to give up her seat to a white man on a bus in Montgomery, Ala., led to the Montgomery bus boycott. This brought Rev. Martin Luther King, Jr. into more active involvement in the civil rights movement and helped bring the segregation of black people in the South to national attention.
In Montgomery in 1955, city buses were segregated, with whites sitting in the front half of the bus and blacks in the back. Rosa Parks, after a long day of work, boarded the bus and sat in the front row of the black section. When the bus filled up with white people, the driver ordered Parks and some other blacks to move back. The others obeyed, but Parks refused. In retaliation, the driver stopped the bus and had Parks arrested. On the day of Parks' trial in December, the local head of the NAACP asked black people to stay off the buses in protest, and as the boycott seemed to be effective, he extended it. The Montgomery bus boycott lasted for 381 days, and the case of discrimination on Montgomery buses went all the way to the U.S. Supreme Court, which upheld a district court ruling that racial segregation was unconstitutional.
Rosa Parks became a symbol for the struggle for civil rights. Due to severe harassment by bigots, she and her family were forced to leave Alabama and move to Michigan, but she continued to promote civil rights for the rest of her life. She received many honors, including the Presidential Medal of Freedom and the Congressional Gold Medal.