Answer. In the 1950s, there was a rule in the US stating that the whites will sit in the front part of the bus while the blacks will sit in the back part of the bus and if the seats in the front become full, then the blacks who are seated at the back have to give up their seats to the whites. Rosa Parks was travelling on a city bus and she refused to give up her seat when a white man approached her. This act by Parks led to huge controversies and problems and eventually she was arrested.