Ernst Mathias Peter von Vegesack (June 18, 1820 – January 12, 1903) was a Swedish Army officer and volunteer in the Union Army during American Civil War and later on was a member of the parliament of Sweden. After his return to Sweden, he was awarded the brevet grade of Brigadier general of volunteers and in 1893 he received the Medal of Honor for bravery in the Battle of Gaines's Mill.[At the outbreak of the Civil War in 1861, von Vegesack left for the United States and joined the Union Army. He became captain of the 58th Ohio Infantry. The same year, he was promoted to major in the staff of general John E. Wool. First he served in Fort Monroe.[3] As an aide-de-camp (ADC) to Joseph K. Mansfield he took part in the artillery bombardment of Newport News. In 1862 he resigned, but then he joined Major General George B. McClellan in his siege of Yorktown. As an ADC to Butterfield he took part in the battles of Hanover Court House, of Seven Pines and of Fair Oaks. He was at the Battle of Mechanicsville, Gaines's Mill, Savage's Station, and Malvern Hill. Vegesack was appointed colonel of the 20th New York Infantry, the German "Turner" regiment. He was given the command over the 3rd brigade in General William Farrar Smith's division of the 6th Army Corps. He took part in the Second Battle of Bull Run. He captured the heights outside Jefferson, Maryland. He displayed bravery at Antietam.[4] Vegesack was in the Battle of Fredericksburg. In May 1863 Vegesack's regiment was a part of Joseph Hooker's left wing in the Battle of Chancellorsville.Vegesack resigned from the Union Army on June 1, 1863 and returned to Sweden.[5] On February 22, 1866, President Andrew Johnson nominated von Vegesack for award of the brevet grade of brigadier general of volunteers, to rank from March 13, 1865 and the United States Senate confirmed the appointment on April 10, 1866.[6]For his service in the Union army, and for repeated acts of courage he was given Sweden's highest medal for bravery, the För tapperhet i fält (For valour in the field) in gold upon his return to Sweden.