Gen. William T. Sherman in 1863: “I bespeak for him the friendship of all true men who esteem honorable military service as the best proof of honest merit.”

“It affords me pleasure to bear my testimony to the special gallantry of Col. Sullivan of the 48th Ohio at the Battle of Shiloh and to the zeal he always manifested in the service of the United States while in command of his regiment.”

Peter John Sullivan got his first military experience during the war with Mexico, rising to the rank of major. Following his military service he was appointed one of the official stenographers of the U.S. Senate. In 1848 he moved to Cincinnati, Ohio, where he studied law, set up a practice, and was a draughtsman for the United States topographical corps. When the Civil War broke out Sullivan expected a commission in the Union Army. William Dennison, the Republican governor of Ohio, suspected Sullivan, a Democrat, of harboring Confederate sympathies, and prevented Sullivan from getting a commission. Sullivan raised four regiments at his own expense to dispel the suspicion. Sullivan was named lieutenant colonel of the 48th Ohio Volunteer Infantry on November 23, 1861, some sources claim at the insistence of President Abraham Lincoln, Lincoln having heard of Sullivan’s ardent support of the Union.

Sherman: “I bespeak for him the friendship of all true men who esteem honorable military service as the best proof of honest merit.”

On January 23, 1862, Sullivan was promoted to colonel and given command of the 48th which was attached to the 4th brigade in William T. Sherman’s 5th division of Ulysses S. Grant’s Army of the Tennessee. On the morning of April 6, Confederate forces under Gen. Albert Sidney Johnston attacked the Union army at Pittsburg Landing, beginning the Battle of Shiloh. The 48th repulsed several Confederate attacks, and it is believed that one of its members was responsible for killing General Johnston. Confederate forces eventually drove the 48th from its position, but late in the day, the 48th as well as the 24th Regiment Ohio Volunteer Infantry and the 36th Regiment Illinois Infantry launched a vital counterattack, stalling the Southerners’ advance. On April 7, the 48th again engaged the Confederates, helping the Union forces to drive the Southerners from the battlefield. At the Battle of Shiloh, the 48th lost approximately one-third of its active soldiers. It is no exaggeration to say that the 48th Ohio played a key role in forestalling a Union disaster that this key moment in the war.

At Shiloh Sullivan had four horses shot out from under him, was wounded three times, and captured a Confederate flag. His wounds prevented him from taking active field command again although he was with the 48th during the siege of Vicksburg. He served for a time as post commander at Memphis, Tennessee, and Fort Pickering while they were in Union hands. He resigned from active duty on August 7, 1863, and Sherman wrote him this strong and moving letter of recommendation.

Autograph letter signed, Headquarters 15 Army Corps, Camp Memphis, TN, October 7, 1863, being a recommendation for Sullivan. “It affords me pleasure to bear my testimony to the special gallantry of Col. Sullivan of the 48th Ohio at the Battle of Shiloh and to the zeal he always manifested in the service of the United States while in command of his regiment. By reason of a wound he received at Shiloh he has resigned and resumed his practice of law in civil life. I bespeak for him the friendship of all true men who esteem honorable military service as the best proof of honest merit. I commend him personally to my friends in Memphis and everywhere.” The letter is unpublished and previously unknown.

Sullivan spent the remainder of the war as a judge on a military court of claims. He was brevetted brigadier general of volunteers on March 13, 1865. President Andrew Johnson appointed Sullivan Minister to Colombia shortly after the end of the war. He was reappointed to the same post after Grant became president in 1869. He resigned soon after however due to his frail health. He had never fully recovered from his wounds.