I have been researching the Shawens as one of my ancestral relatives Jane W. Hamilton of Loudoun Co, VA married George W. Shawen and they lived in Licking Co, OH; Cass Co, IL; and Barton Co, MO. I think your "Carl Oliver Shawen" is actually their youngest son Charles Carroll Shawen, born abt. 1842 Licking Co, OH.
I have a marriage record for him in Menard Co, IL 1863: Illinois Statewide Marriage Index Groom Bride Date Volume Page Lic No. County SHAWN, CHARLES SMYERS, ELIZABETH1863-12-24 A 254 1693 MENARD
and the following census records:
1850 OH Licking Co Chatham p.443 George W. Shawen 53 M teacher MD Jane W. 51 F VA Catharine 20 F VA George W. 12 M OH Charles C. 8 M OH
1860 IL Cass Co Richmond p.140 indexed as “Sherven” George W. Shawen63 M MD Jane W. 60 F VA Kate J. 24? F VA George 22 M OH Charles C. 19 OH William M. Clark 7 M OH Amelia C. Clark 11 F OH
1870 MO Jasper Co Carthage p43b C C Shawn 27 OH Elizabeth Shawn 24 IL Kitty Shawn 5 IL Lavina Shawn 2 MO Ruth Shawn 2/12 MO
1880 MO Jasper Co Duval p316b Carrel S... 40 A. Elizabeth S... 33 W. Kitty S... 14 M. Rovenna S... 12 M. Ruth S... 10 E. John S... 7 L. William S... 3
1900 IL Morgan Co Alexander p6b S H Shawen 58 [Charles Carroll Shawen] Elizahet Shawen 65 William L Shawen 22 Josephine Shawen 17
George W. Shawen b. abt. 1797 MD d. aft. 1871 Probably Barton Co, MO, was the son of Cornelius Shawen 1772-1820 of Loudoun Co, VA and Anna Maria Mahn or Maine.
George & Jane Shawen had four children that I've been able to find: James William Shawen 1822-1896 Catherine J. Shawen 1830-1915 m. Jeptha Dudley Pilcher George W. Jr. Shawen 1838-aft. 1870 Charles C. Shawen 1842- aft. 1900.
I can send you more details if you're still interested. Do you have details on Charles/Carl's death in the mine accident in California? I am very interested in finding out more about that.