Franz Sigel (1824-1902) was a graduate of the German Military Academy who came to the United States by way of Switzerland and England after resigning his commission in the German Army and fighting in that country's failed revolution. As a director of schools in St. Louis, he was influential in the emigrant community there and drew Missouri Germans to the Union cause when he openly supported it in 1861. Although his generalship was not what one would have expected from a German-trained military officer, he nevertheless rose to corps command in the Army of the Potomac, a position he held until poor health forced him to take on lesser duties in the winter of 1863.
General Franz Sigel
General Officers of the Civil War
After suffering his most famous defeat at the hands of Confederate General John C. Breckenridge at the Battle of New Market in 1864 and only delaying General Jubal Early at Harpers Ferry, he was relieved of command for "lack of aggression." Sigel resigned from the army in May of 1865, moving to Baltimore and becoming a journalist. He eventually moved to New York City, where he continued in publishing and became a popular draw in the lecture halls.
Sigel's German troops were proud of serving under one of their own, and their rallying cry, "I fights mit Sigel," became well known in the Army of the Potomac.
The "Fighting Joe" mentioned in the last verse is Union General Joseph Hooker, which dates the composition of this song to some time before the Battle of Chancellorsville, when Hooker commanded the Army of the Potomac.
For more information on Germans in the Civil War, visit Scott Franks' excellent Web site of the same name.
"I Fights Mit Sigel"