Why was the US worried about the Soviet Union?

The Soviet Union was building a nuclear arsenal.

Explanation:

The Cold War.

( sorry my answer is short they wont let me do just war so ignore this) xd

the civil war was a fulfillment and completion of the constitution, not a revolution against it. changes in culture and society surely affected political life. lincoln hoped to bring the north and south together after the war by healing the nationand making people lose their resentment.

hope this you out just took thus test a min go and mad a 100