Gen. August Willich, Louis Blenker, Max Weber and Alexander Schimmelfennig. In its two years of operation, all but one commander of the XI Corps, which played a decisive role in the battles of Chancellorsville and Gettysburg, were Germans, including Sigel and Schurz.
The text highlights that the XI Corps, which played a crucial role in battles like Chancellorsville and Gettysburg, was primarily commanded by German officers for its two years of operation.  Notable figures like Sigel and Schurz were among those who led this corps.