Up until 1955, all places in America had separate places for blacks and whites: different drinking fountains, different restrooms, different sides of the buses, schools, and even different neighborhoods.
But on December 1, 1955, Rosa Parks, a local black seamstress of Montgomery, Alabama, refused to give up her seat to a white man. She was arrested and fined that same day for breaking a "city ordinance." This incident led to the Montgomery Bus Boycott. Led by Dr. Martin Luther King, Jr., many black people in Montgomery refused to ride buses. They,instead, carpooled, walked, and took taxis. Because of the sudden decrease of bus riders, bus companies began to lose money. In order to regain financial strength, the law changed for all people to be equal and for non-segregation.
Rosa Parks' refusal of her bus seat led to the boycott which led to legalizing non-segregation. She remains important in our society not just because of her standing up to unjust laws, but also, Rosa Parks fought for civil rights and gave speeches to teach young children about the history of our country.
You can read Julien G.'s related story about Dr. Martin Luther King.
Watch this video about what happened on December 1, 1955.