"They interact with each other" should be the answer.
Most died of hunger or disease, and the cold winter didn't help. Hope this answers your question :D
Answer:
Growth of Industrialized cities.
Answer:
The political problems after the Civil War were twofold. The first crisis involved how to abolish slavery. Second, the government agonized over how to bring the Confederacy back into the Union. The slavery issue was solved with the passage of the Reconstruction Amendments, but it would be a century before all African Americans completely enjoyed these rights.
So, I believe that there were two major problems at the time.
Federal government includes all 50 states while state government only includes the state. The state makes its own laws and has its own governor, mayors, etc. Federal follows the basis of the constitution.