Civil War Union Brigadier General. A successful pre-War fur merchant based in what is now West Virginia, he was appointed as Colonel and commander of the 7th Ohio Volunteer Infantry, a unit he helped recruit, and whose Lieutenant Colonel was future United States President James Abram Garfield. Stationed near Kessler’s Cross Lanes in (West) Virginia in August 1861, the unit got its first experience in the war when it was surprised and routed by a Confederate brigade under Brigadier General John B. Floyd. In early 1862 he was advanced to brigade command, and fought against Major General Thomas “Stonewall” Jackson in his brilliant Valley Campaign. He commanded the Union Forces in the June 9, 1862 Battle of Port Republic, and was defeated by Jackson the last battle of the Campaign. On the previous May 14 he had been commissioned Brigadier General, US Volunteers. In August he was assigned to command the 1st Brigade, 3rd Division of the Army of the Potomac’s V Corps, whom he led in the Battles of Antietam, Fredericksburg and Chancellorsville. At Antietam, his brigade was held in reserve with the rest of the V Corps, and saw no action, but at Fredericksburg it took part in the 5th Union assault on the impregnable Confederate position behind the famed Stone Wall, and sustained heavy casualties (General Tyler himself being wounded). At the Battle of Chancellorsville, the First Brigade helped hold the right flank of the III Corps line, fighting the Confederate brigade of Brigadier General Alfred Colquitt to a standstill, and sustaining 240 casualties. After the battle three of his four regiments were mustered out of service, leaving him without a command. At the end of June 1863 he was assigned to command the defenses of Baltimore, Maryland, a post he would hold until the end of the War. In March 1865 he was brevetted Major General, US Volunteers, and was mustered out of service in August of that year. He remained in Baltimore for the rest of his life (having married a local woman during the war), and became one of its prominent citizens. He served a term as the city’s Postmaster, and died there in 1891.