African Americans joined the Union arm in droves to fight for the abolition of all slaves in America, so they fought harder than most regular Union troops because they were fighting for their futures and lives (the South would enslave them again if the Union lost).
Answer& Explanation: It was different because at the time they were not free. As you may know the civil war was the war that ended slavery. It was a battle between the north and the south. President Lincoln told the African Americans to fight because the war was for them. Also I'm pretty sure back then majority of of the north were pampered so not many were soldiers. The south was the exact opposite with many men that signed up just so they could fight in the Civil War.
The nations had different systems of government and different economic systems. The USSR hated the U.S and it's capitalism, hoping to one day crush it but with the fall of the USSR in 1991, It was a monumental victory for capitalism over communism and socialism.
