Answer:
Is this even a question. . _.
1. Ku Klux Klan (KKK)
2. Andrew Johnson
3. 15th Amendment
4. Black codes
5. Nat Turner
6. Seven Martyrs
7. 10% Plan
8. Friedman’s Bureau
9. West Virginia
10. Jefferson Davis
11. 13th Amendment
12. John Wilkes Booth
13. Monitor
14. Joint Committee of 15
15. First Reconstruction Act
16. 14th Amendment
Considering that the original 13 colonies were founded in the eastern seaboard of the country and that until the post WWII period the major population centers shifted from the East to the West of the country it is only natural and logical. Indeed, the eastern seaboard was the most industrialized and populated area of the USA for a long time and most immigrants entered the country through New York. Pennsylvania was also heavily industrialized and a major mining area.
With more immigrants pouring in every year, the potential for more criminal acts increased and to keep up, more prisons were necessary. There is also the huge factor of labor rights activism, which was criminalized by employers and judges in order to keep workers docile and submissive. Many strikers and labor unions were incarcerated as well and more prisons were needed for that purpose.