What is meant by the “nadir” of race relations?

The nadir of race relations refers to the lowest point in relations between the white and black communities.

they killed other men

explanation:

president thomas jefferson hoped that the embargo act of 1807 would the united states by demonstrating to britain and france their dependence on american goods, convincing them to respect american neutrality and stop impressing american seamen. instead, the act had a devastating effect on american trade.