These laws stemmed from the previous slavery period in which African Americans were the labor force in America. These laws made blacks a second class citizen and created many racial tensions.
2) Apartheid (1900-Present)
This was the a racial system based in segregation and discrimination that occurred in South Africa which resulted in the oppression of the natives.
Many opposing actions took place against Apartheid including many countries that blocked trade with South Africa until the Apartheid officially ended in 1994 with the election of the first black president Nelson Mandela.