The American Civil War in the East
It was just 100 miles from Washington to the Confederate capital at Richmond, Virginia, but the trip took many twists and turns in its four long years. The Eastern Theater of the American Civil War ran from southern Pennsylvania to Virginia's North Carolina border and from Chesapeake Bay to the mountains west of the Shenandoah Valley. It included the first big battle at Bull Run, the deadliest single day at Antietam, and the greatest battle of the war at Gettysburg.
There were other theaters and armies, and some of the most decisive blows of the war were elsewhere. But to many the heart and soul of the Civil War was the contest between the Union Army of the Potomac and the Confederate Army of Northern Virginia.
This site currently includes two sections that are mostly complete:
United States Armies and Departments
Month-to-month orders of battle from the army and department level down to individual regiments and batteries
United States Regiments and Batteries
Historical timelines for Union regiments and batteries.
West Point officers who served in the Civil War
Lists United States Military Academy classes
from 1802 until 1861 with information about whether each officer served in the war, on which side, and highest rank attained.