During the 1770s, he was a delegate to the Continental Congress. In the 1780s, Adams served as a diplomat in Europe and helped negotiate the Treaty of Paris (1783), which officially ended the American Revolutionary War (1775-83). From 1789 to 1797, Adams was America's first vice president.
There are several ways that Southern states undermined the rights of African-Americans. Here are just a couple:
1) Poll taxes- These taxes were forced onto Southern citizens in order to vote in elections. These negatively impacted African-Americans, especially after the Reconstruction period. This is because former slaves were still struggling to earn a fair wage for their work.
2) Literacy tests- These were written exams given to individuals before they voted. If they did not pass, they did not get to vote. This undermined the ability of African-Americans to vote, as many of them did not have formal schooling experience and could not read/write.