It's been 57 years since the day Rosa Parks refused to give up her seat on a bus.
Yesterday the White House marked the anniversary by tweeting a picture of Barack Obama sitting in the bus where Parks stood her ground.
At the time the photo was taken, ABC News reported:
"I just sat in there for a moment and pondered the courage and tenacity that is part of our very recent history but is also part of that long line of folks who sometimes are nameless, oftentimes didn’t make the history books, but who constantly insisted on their dignity, their share of the American dream".
As a result of refusing to move to the back of the bus, Parks was arrested.
Mrs Parks was not the first person to defy the law, however. Two black women, Claudette Colvin and Mary Louise Smith, had already been arrested for the same offence.
Parks' arrest led to a 381-day boycott of the Montgomery bus system.
It was organized by a then unknown Baptist minister, one Reverend Martin Luther King.