What was the most difficult challenge did the united states have during the 1970's?

If you're talking about edg, then the answers are a,b,d,f

Explanation:

doing it rn

here are some events that to cause increased conflict between the north and south

1) mexican cession- gaining modern day california, utah, arizona, and new mexico from mexico. caused southern and northern politicians to fight over whether or not there would be slavery in these newly acquired territories.

2) uncle tom's cabin- this famous book described the cruelty of slavery in the south during the antebellum period, causing more northerners to support abolition and southerners to resent the book as they felt it unfairly depicted southern society.

3) kansas- nebraska act- disagreements over whether or not kansas and nebraska would be free or slave states caused issues between northern and southern politicians in congress.

4) bleeding kansas- this fighting took place in kansas after congress allowed this territory to vote on whether or not they would have slavery. citizens were killed and buildings were destroyed during this fighting.

confedracy

supported slavery

upheld the supremacy of federal laws

believed states should be able to nullify federal laws

union

wanted to abolish slavery

supported high tariffs

upheld the supremacy of federal laws