Ulysses grant
Grant commanded the Northern army during the US Civil War. Giap commanded the Northern army during the Vietnam War.
The Commander In Chief of the Union army during the Civil War was President Abraham Lincoln; the ranking general in the field was Ulysses S. Grant.
The Army of Northern Virginia was commanded by Robert E. Lee
Sherman's army was the civil war army commanded by General William Tecumseh Sherman.
Ulysses S. Grant commanded the winning union army and was swept into the presidency because of his victory.
He was in command of his own Army - the Army of Northern Virginia.
The first General in Chief of the Union Army was Lieutenant-General Winfield Scott.
The overall commander of the Confederate States of America during most of the Civil War was General Robert E. Lee.
Robert E. Lee was the general of the Confederate Army for the vast majority of the Civil War.
Ulysses S. Grant
The Army of the Potomac, commanded by General George Meade, but closely supervised by the Union General-in-Chief Ulysses S. Grant.
There were several generals during the Civil War who were leaders of confederate troops, but probably you are thinking of Robert E. Lee, who commanded the Confederate Army of Northern Virginia.