The Union forces at Martinsburg were commanded by Brigadier General Julius White. Union troops there outnumbered the Union forces at Harper's Ferry. As Halleck and McClellan argued over Harper's Ferry, General White had received no orders from Washington DC. In that situation, General White decided to remain where he was in Martinsburg.
There was no Union General on the spot. The Sumter garrison was commanded by a Major Anderson. The General-in-Chief in Washington was Winfield Scott.
The Union garrison was commanded by Major Anderson. The Confederates in Charleston were led by General P.G.T. Beauregard.
Confederate General Lee had sent a three military force to capture Martinsburg and Harper's Ferry in the middle of September, 1862. The Confederate commanders sent on this mission had been out maneuvered by Union General Julius White. He had been the commander at Martinsburg and on the night of September 11, 1862 evacuated Martinsburg to consolidate his forces with Colonel D. S. Miles who commanded the Union forces at Harper's Ferry. This almost doubled the Union troops there to 13,000 men.
There wasn't one. The small garrison was commanded by Major Robert Anderson.
The Union garrison on the island of Fort Sumter in Charleston Harbour. It was commanded by Major Anderson.
The Union army under Ulysses Grant, who defeated the Confederate garrison commanded by General John C. Pemberton, the overall area commander being Joseph E. Johnston (Confederate).
Sumter was a tiny US Army garrison on an island in Charleston Harbour, commanded by a Major Anderson. There was no General on the spot. Presumably, Anderson's orders came direct from Washington, ultimately from the General-in-Chief, Winfield Scott.
No he commanded the Union Army
The Confederate General commanding the Vicksburg garrison was John C. Pemberton, supervised by his area commander Joseph E. Johnston. The Union force was commanded by Ulysses S. Grant.
General Irvin McDowell.
Meade commanded the Army of the Potomac at Gettysburg.
The commanders for the Confederates were General Joseph E. Johnston and Brigadier General Pierre Beauregard at First Bull Run. The Union army was commanded by Brigadier General Irvin McDowell.