President Abraham Lincoln Appoints the Son of David Wilmot’s Law Partner an Officer in the Prestigious 5th Regiment of U.S. Cavalry

He also won awards for bravery in the Antietam and Gettysburg campaigns, and ended up leading the regiment

Julius Wilmot Mason was named for his father’s law partner, David Wilmot, who as a congressman introduced the famous Wilmot Proviso. The Proviso, a proposal banning slavery in the territories obtained from Mexico in the Mexican War, was one of the major events leading up to the Civil War.

Answering President Lincoln’s initial call for volunteers, Mason was appointed a second lieutenant in the 5th U. S. Cavalry on April 26, 1861. Mason had had plenty of military training while at the Kentucky Military Institute, and the ranks of the Regular cavalry regiments were badly depleted by the departure of southern officers and the assignment of Regular officers to command volunteer regiments. The 5th U. S. Cavalry, in particular, had been badly hit, losing, among others, Col. Albert S. Johnston, Lt. Col. Robert E. Lee, Maj. William J. Hardee, Capts. Earl Van Dorn and Edmund Kirby Smith, and Lts. John Bell Hood and Fitzhugh Lee to the Confederacy.

Mason fought at First Bull Run, where he drew praise for his “daring intrepidity”, and was promoted to first lieutenant. He and the regiment actively participated in McClellan’s 1862 Peninsula campaign, participating the siege of Yorktown. The regiment was active in the Antietam campaign, and in May 1863 took an active part in the Stoneman Raid. He commanded a squadron that served as the Army of the Potomac’s Cavalry Corps’ advance guard at the beginning of the raid. While his squadron was isolated from the main body, Mason captured nearly the entire complement of men assigned to a Confederate battery, and was only prevented from taking the guns by the arrival of the rebel cavalry. Mason held his position until the rest of the U.S. Cavalry Corps crossed the river. As the regimental historian of the 5th U. S. Cavalry put it, “This was one of the most gallant dashes made by any part of the regiment during the war.”

Mason then participated in the June 1863 Battle of Brandy Station, where he earned a brevet to major for gallant and meritorious services. When Capt. James E. Harrison suffered a debilitating sunstroke just after Brandy Station, Mason assumed command of the 5th U. S. Cavalry, and led it during the June 17, 1863 Battle of Aldie, in the fighting on South Cavalry Field at Gettysburg on July 3, and throughout the Gettysburg campaign. He earned a brevet to lieutenant colonel for gallant and meritorious service at the August 1, 1863 fight at Brandy Station. Mason led the regiment through the Bristoe Station and Mine Run commands. In March 1864, he was selected to command the bodyguard for Lt. Gen. Ulysses S. Grant , and served in this important role until the end of the Civil War. He was afterwards active in the Indian Wars and ended his service as a colonel.

Document signed as President, on vellum, complete with engravings of an eagle, flags, and military accoutrements, Washington, December 26, 1861, appointing Mason “First Lieutenant in the Fifth Regiment of Cavalry”, and “to rank as such from the first day of June 1861.” It is countersigned by incoming Secretary of War Edwin M. Stanton.

It is interesting to note that Stanton did not officially assume his office as Secretary of War until January 20, 1862. Thus this document, prepared on December 26, 1861 while Stanton’s predecessor Simon Cameron still nominally held the post but after he had stopped doing ministerial duties, was waiting on Stanton’s desk when he walked into his office for the first time in January 1862. It was clearly one of the first documents Stanton signed as Secretary of War.