Throughout the early part of his public life, Sigel's motives were sincere. Inspired by the liberal themes of the French Revolution of 1848, he genuinely supported the Baden revolution and the war against the Confederacy. However, by 1862 he began to manipulate the press and the public that had showered him with undeserved praise. By 1865 most of his supporters and all of his superior officers abandoned him because they came to realize his accomplishments did not match the promise of his publicity. Nevertheless, he was the most famous German-American general in the Union army and the most visible symbol of immigrant support for the Union cause.
Earl J. Hess, "Sigel, Franz," American National Biography Online, February 2000, http://www.anb.org/articles/05/05-00716.html.