Complex sentence: The controversy lies in the personal history of General Forrest; after his military duty was over, he became the first Grand Wizard of the Ku Klux Klan (though soon after called for the Klan to disband).
Split into simpler sentences: The controversy lies in the personal history of General Forrest. After his military duty was over, he became the first Grand Wizard of the Ku Klux Klan (though soon after called for the Klan to disband).