Why did slavery come to a halt in the 1750s?

It did not come to a complete halt but it did slow down a little. This is because of the Stono Rebellion which took place from 1739-1750. The slave trade came to a halt during the Revolutionary War

It wasn't ended yet, but around that time confederates and northern states started to have the civil war, and slaves were rebelling. The true ax was Abraham Lincoln's involvement in making the 13th ammendment. Many consider him one of the best presidents of all time because of this, however racial d-crimination would still continue.

Explanation:

russia because it is the biggest state