In the middle half of the war (1862-64) Halleck was General-in-Chief of all the Union armies.
He was a respected intellectual, but a poor leader, and he feuded badly with other Generals.
However, he was gracious enough to accept the job of Chief-of-Staff under his one-time subordinate U.S. Grant.
The left side
He was the lead general for the union side (north).
Nat Turner wasn't alive during the time of the Civil War, but if he was he would be on the Union's side.
he was on the north side he was on the north side
The Union General Ambrose Burnside.
The former slaves should be on the South's side to fight in the Civil War.
He was on the South side.
It was Robert E. Lee
Confederate
confederate (south)
Confederates
There was no "good side" in the civil war. There are no good or bad people. People just do what they think is best.