Correspondence to and from Dr. Gray concerning his research and writings. Correspondents include Mark Brown, members of the Bruguier, Galpin, and Reynolds families, Federal Archives, local and state archives, Northwestern University, and publishers. Topics include extensive genealogical research, particularly on the Bruguier, Galpin, and Reynolds families, comments on Dr. Gray's writings by colleagues and publishers, a limited amount of material regarding his patents and his retirement from Northwestern University, and personal correspondence.