"West Virginia Marriages, 1780-1970," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:FRY7-MJM : 4 December 2014), J M Cresap and M A Whittaker, 1870; citing Marshall, West Virginia, United States, , county clerks, West Virginia; FHL microfilm 853,805.
"Ohio Marriages, 1800-1958," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:XD45-KD2 : 8 December 2014), James M. Cresap in entry for Wilbur H. Snow and Cora Cecela Cresap, 05 Jan 1905; citing , Belmont, Ohio, reference 2:3X581QC; FHL microfilm 902,150.
"California Marriages, 1850-1945," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:V2Z7-WFY : 6 December 2014), James M. Cresap in entry for Edward Charles Williams and Minnie Virginia Cresap, 23 Nov 1911; citing Pasadena, Los Angeles, California; FHL microfilm 1,033,227.
Cresap, Joseph Ord, and Bernarr Cresap, comps. The History of the Cresaps. (The Cresap Society, McComb, Mississippi, 1937). Pages 319, 357. Person #545.
Obituary of Margaret A. Whitaker Cresap, Wheeling Register, WV, Thur 03 Sep 1896
It may be possible to confirm family relationships with James by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
However, there are no known yDNA or mtDNA test-takers in his direct paternal or maternal line.
It is likely that these autosomal DNA test-takers will share DNA with James: