Winfield Scott: July 5, 1841 - November 1, 1861
There were several commanders of the Union Army. Commanders included Winfield Scott, George B. McClellan, Henry W. Halleck, and Ulysses S. Grant.
1864
George McClellan
The first assault on Charleston by the Union forces was on July 11, 1863.
Irvin McDowell
The commander of the Union Army at First Bull Run (First Manassas) was Major General Irvin McDowell.
The job of commander of the Union Forces was offered to Robert Edward Lee.
Robert Anderson was the commander at Ft. Sumter .
U.S. Grant
General George Meade was the commander of the Union forces at Gettysburg.
That depends on which Union forces. U.S. Grant was overall commander of Union forces.
U.S. Grant
Ulysses S.Grant
John Pope
As President, he was Commander-in-Chief of all Union Armed Forces.
Ulysses S. Grant
George McLellan
Ulysses S, Grant