The union is the North and the confederacy is the south
explained:
The American Civil War was fought between the United States of America and the Confederate States of America, a collection of eleven southern states that left the Union in 1860 and 1861. The conflict began primarily as a result of the long-standing disagreement over the institution of slavery.
You could start off with the news report about how Soviet and U.S almost started another war due to a missile crisis with Cuba or how soviet's government is different from ours. Basically compare and contract Soviet and U.S.
Hopefully this can get you a head start Have a great day :)