The Union Army had only 360 total soldiers die from any cause.
Among memorable field leaders of the army were Nathaniel Lyon (first Union general to be killed in battle during the war), William Rosecrans, George Henry Thomas, and William Tecumseh Sherman
  The pre-war Regular Army numbered approximately 16,400 soldiers, but by the end while the Union Army had grown to over a million soldiers, the number of Regular personnel was still approximately 21,699, of whom several were serving with Volunteer forces

