Rosa Parks, a very historical figure, refused to give up her seat on the bus for a white man one day. She was eventually arrested because of this.
Even so, she brought courage to other African Americans to begin boycotting the buses.
This meant not traveling by bus at ALL. African Americans from all over the United States began carpooling and walking instead of using public transportation. This resulted in a major loss for bus companies who lost an extrememly large amount of money without the African Americans' money.
Eventually, before becomming completely bankrupt, officials allowed integration on buses. This meant that no matter the race, you could sit ANYWHERE (not any specific section) on the buses. This was a major victory, in my opinion, for civil rights.