When he arrived in the U.S. from Germany in 1852, Franz Sigel brought with him a reputation as a fighter and a liberal. Sigel graduated from Karlsruhe Military Academy, and retired from the German army in 1847. He became minister of war for the unsuccessful Revolution of 1848 against Prussia. He fled Germany, finally arriving (by way of Switzerland and England) in St. Louis, Missouri, where he would teach school until 1861. He became an influential leader among the area's large German population. He was commissioned brigadier general August 7, 1861, and was promoted to major general less than a year later, on March 22, 1862.
Sigel served under Brig. Gen. Nathaniel Lyon in the capture of the secessionist Camp Jackson in St. Louis and at Wilson's Creek. On March 8, 1862, at Pea Ridge, Sigel gave his finest performance. There, under Maj. Gen. Samuel R. Curtis, he commanded two divisions and personally directed the Union artillery in the demoralizing slaughter of Maj. Gen. Earl Van Dorn's Confederates. He was then transferred east, where he served in the Shenandoah Valley against Maj. Gen. Thomas J. "Stonewall" Jackson, and commanded the I Corps in Maj. Gen. John Pope's Army of Virginia at Second Bull Run; he also briefly led the XI Corps. On May 15, 1864, as commander of the Department of West Virginia, Sigel's military usefulness came to an end, however, when his forces were defeated at New Market, Va., a battle made famous by the charge of the Virginia Military Institue cadets. Sigel, relieved of field command shortly after the battle, resigned his commission May 4, 1865, and reentered civilian life. He died in New York City on August 21, 1902.
Sigel was an odd combination of ineptitude and ability, with a military record, aside from his performance at Pea Ridge, that was little more than mediocre. He unquestionably helped the Union cause, however, by rallying German-Americans to take up arms against the Confederacy, holding their loyalty to the end.