Since humans weren't around to kill them off...
hope this helps :)
Answer:
Reconstruction Plan
Explanation:
in 1865 President Andrew Johnson implemented a plan of reconstruction that gave the white south of free hand in regulating the transition from slavery to freedom and offered no role to blacks in the politics of the South.
The three steps were 1. Block off the pots in the south or confederacy and cut off its trade. 2. Divide the confederacy by gaining control of the Mississippi river. 3. The north invaded the south both east and west. These are the 3 steps to the anaconda plan for the Antietam part of the civil war. Hope this helps! :D