In his original draft of the Declaration, Jefferson condemned the slave trade carried on by the British. (Yes, Jefferson himself owned slaves he had inherited, but saw an eventual emancipation of slaves as something that would need to be done over time.) The paragraph in the draft of the Declaration said that the King of England "has waged cruel war against human nature itself, violating its most sacred rights of life and liberty" by capturing, transporting and selling human beings from the distant land of Africa. He called the "market where men should be bought and sold" an "execrable commerce" carried on by authority of the British crown. ("Execrable" is an adjective related to excrement -- something extremely nasty.)
Georgia and South Carolina would not join in voting for independence from Britain unless the paragraph about the evil of the slave trade was omitted, and so it was omitted from the final version.
The Consitiution. Inflamed by the king's stonewalling of their appeals, the Founders embedded the right to petition into the Constitution by way of the First Amendment.
In the south of course. Jim Crow laws where laws that said that limited the possibilities of African Americans (Jim Crow is just another name for African Americans).