Winfield Scott: July 5, 1841 - November 1, 1861
Irvin McDowell
McDowell
The first commander of the entire Union army was Winfield Scott.
Irvin McDowell
On the field it was Irwin McDowell.
The first commander of the Union troops during the American Civil War was Brigadier General Irvin McDowell. He led the Union forces at the First Battle of Bull Run (also known as First Manassas) in July 1861. McDowell's command faced significant challenges, and after the Union defeat in that battle, he was eventually replaced by General George B. McClellan.
The Union commander was Ulysses S. Grant
Ulysses S. Grant
Ulysses S. Grant
Irvin McDowell
Major General John F. Reynolds
US Naval commander Samuel P. Lee was the first Union commander to demand the surrender of Vicksburg Mississippi. This demand was made on May 18, 1862. Lee was the captain of the USS Oneida. Just prior to this the City of New Orleans was captured and Baton Rouge also fell. The Union navy then set its sights on Vicksburg.