Maj. Gen. Ulysses S. Grant did not like McClernand and after Sherman and Admiral Andrew H. Foote both voiced their opinions that McClernand was unfit to command, Grant personally took command of the expedition against Vicksburg and the old XIII Corps and XV Corps were returned to the Army of the Tennessee on January 12, 1863.
Generalmajor Ulysses S. Grant kunne ikke lide McClernand og da både Sherman og Admiral Andrew H. Foote udtrykte den holdning, at McClernand ikke var i stand til at lede hæren tog Grant selv kommandoen over ekspeditionen mod Vicksburg og de gamle XIII og XV Corps blev ført tilbage i Army of the Tennessee den 12. januar 1863.