Willie Dixon was born July 1, 1915, in Vicksburg, MS.
http://www.allmusic.com/artist/willie-dixon-mn0000959770/biography
Illustration: William Stout / Legends of the Blues

James Cotton was born July 1, 1935, in Tunica, MS.
http://www.allmusic.com/artist/james-cotton-mn0000131841/biography
Illustration: Jack Coughlin / A Brush with the Blues: 26 Portraits

Willie Dixon and James Cotton with Muddy Waters, Sunnyland Slim, Otis Spann, Sonny Terry, Brownie McGhee, and Mable Hillery in 1966 at the Canadian CBC Television studio, recording a portion of a CBC “Festival” series:

http://www.allmovie.com/movie/masters-of-the-blues-v204117