Congress rejects a call by President Lincoln to adopt a standard railroad gauge of 5 feet and adopts the 4 foot, 8 and one-half inches gauge. It is sometimes called the Congressional gauge.
The Conscription Act (National Enrollment Act of 1863) is signed into law by President Lincoln. Congress requires quotas of draftees by state, but allows wealthy Americans the right to buy their way out of service for $300.00. Also called the Draft Act or any number of variations.
Confederate Cavalry under Earl Van Dorn and Nathan Bedford Forrest drive Union Cavalry off on the 4th, then surround and engage the remaining infantry. After heavy fighting on the 5th, the Union garrison surrenders.
President Lincoln issues an order of amnesty for men absent without leave from the Union Army. They must report by April 1st or they will be considered deserters
Ulysses S. Grant renewed his efforts to reach Vicksburg when he tried to push gunboats past Fort Pemberton, near Greenwood. General W. W. Loring ("Old Blizzards") had built and manned the fort to prevent attacks of this nature.
An explosion in the Confederate Ordinance Laboratory on Brown's Island in the James River near Tredegar Iron Works in Richmond kills 69 people, 62 of them women and young girls. A friction primer exploded.
Admiral David Farragut pushes his command vessel, the Hartford and the Albatross past Port Hudson, but Confederate fire seriously damage three other vessels.
William Bensinger, Robert Buffum, Elihu H. Mason, Jacob Parrott, William Pittenger and William H. Reddick are exchanged for Confederate soldiers from the prisoner-of-war camp at City Point, Virginia. Among the first Medal of Honor winners, these men were members of Andrews Raiders
Federal cavalry under William Woods Averall crossed the ford of the Rappahannock River then ran into a Rebel line. After brief but heavy fighting, the Yankees withdrew that afternoon. Major John "The Gallant" Pelham [CS] was killed in this battle. He would posthumously be promoted to Lt. Colonel.
Stymied in his attempt to reach Vicksburg on the east bank of the Mississippi, Grant orders General John McClernand to march south on the west bank to Miliken's Bend