There were several leaders:
Winfield Scott: July 5, 1841 -- November 1, 1861
George B. McClellan: November 1, 1861 -- March 11, 1862
Henry W. Halleck: July 23, 1862 -- March 9, 1864
Ulysses S. Grant: March 9, 1864 -- March 4, 1869
Abraham Lincoln: between McClellan and Halleck
Ulysses S. Grant
During the American Civil War, the primary military leader of the Union was General Ulysses S. Grant, who eventually became General-in-Chief of all Union forces and played a crucial role in leading the North to victory. In contrast, the Confederacy's most prominent military leader was General Robert E. Lee, who commanded the Army of Northern Virginia and became renowned for his tactical prowess. Other notable leaders included Union Generals William Tecumseh Sherman and George McClellan, and Confederate Generals Thomas "Stonewall" Jackson and Jefferson Davis.
General Ulysses Simpson Grant led the Army of the Potomac.
Ulysses S. Grant
Just the American Civil War began, the military leader who would end up becoming the most famous Confederate general, Robert E. Lee, was offered a key position in the Union Army. Despite being personally opposed to slavery and secession, Lee hesitated to accept the position because it would require him to make war against his beloved home-state of Virginia. His hesitation cost him the job, and he went on to serve in the Confederate military.
He was a successful military leader as army commander and as General in Chief of Union Army.
McClellan was a leader of the Union Army.
Jefferson Davis was the President of the Confederate States of America. General Robert E. Lee became the key military leader of the Confederate army. Abraham Lincoln was the president of the Union. General US Grant became the key military leader in the closing 18 months of the war.
Santa Anna was the military leader captured by the Texan army.
Marquis de Lafayette was the French military leader who helped transform the Continental Army. He was a major-general in the Continental Army.
No Union military leader actually had a bodyguard. However, President Abraham Lincoln used the term McClellan's bodyguard to describe the idle army which was being incompetently led by Major General George McClellan.
Ambrose Burnside
The leader of the largest unit of the Roman Army was the legatus
William T. Sherman was a leader of Union soldiers.
Army is part of the military.....sooo you're dumb and it was the Army that fought the Civil war. you had the confederate Army as well as the Union Army, battled against eachother....north was the union and the south was the confederate.
Joseph Hooker
George B. McClellan was a general who fought in the Civil War. He fought on the side of the Union Army, but is generally regarded as a somewhat ineffective military leader.