There were Mitchell County men in the following regiments:
Another place to check for Georgia confederate soldiers is the Georgia Civil War Soldiers Index in the GAGenWeb Archives.
World War II
The National Archives has two series of books for casualties of WWII. Digital copies of the pages of these books are available at the National Archives web site (see links below).
Korean War and Vietnam War
State level casualty lists for the Korean and Vietnam Wars are available at the National Archives web site. These lists include all U.S. military personnel who died from hostile action (including missing and captured) in the Korean War, 1950-1957 as well as all U.S. military personnel who died (including missing and captured declared dead) as a result of the Vietnam conflict, 1957-1995, deaths as of November 1997.