Laura,

The only George W. Ring that I can find, who was a Captain in the Union army and whose unit fought at Vicksburg, is the following man:

Name: George W Ring
Residence: Milwaukee, Wisconsin
Enlistment Date: 25 October 1861
Service Record: Enlisted as a Private on 25 October 1861
Enlisted in Company I, 2nd Cavalry Regiment Wisconsin on 25 October 1861.
Promoted to Full Lieutenant 1st Class on 26 November 1861
Promoted to Full Captain on 24 September 1862
Promoted to Full Major on 15 February 1865 (Not Mustered)
Mustered out Company I, 2nd Cavalry Regiment Wisconsin on 25 February 1865

Is this the man, for whom, you're looking?

Jim Martin