The family may want to look at publications on the History of the area and people found here
http://www.moniteau.net/hsoclib.htm
http://www.moniteau.net/cemeterymap.htm map of cemeteries in the county
https://cooper.mogenweb.org/Cemeteries/HOPEWELL%20CHURCH%20CEMETERY.pdf this lists him in Hopewell cemetery.
https://www.familysearch.org/wiki/en/43rd_Regiment,_Enrolled_Missouri_Militia_(Union)
http://www.civilwararchive.com/Unreghst/unmoinf4.htm#38
http://www.moniteau.net/historicmap.htm
The following 2 are from user donated data and need to have data verified. But there is a lot of date info and names so you might have a fighting chance.
https://sites.rootsweb.com/~gowenrf/dcuz003.htm I saw this and the name and date of birth are close
I am seeking the identify of the father of William Gowen who was born about 1802 in Pittsylvania County, VA. When William Gowen applied for a marriage license there in 1821 to marry Susannah Bruce, his mother "Anna Goin" wrote a note to the county clerk giving her consent. The bride's father, Thomas Bruce, also wrote a note to the clerk giving his consent, sug-gesting that Susannah was also underage. William Abston was security for the marriage. William Gowen and Susannah Bruce Gowen were the parents of William Henry Gowen, my g-gf, born in 1822. I am ready to pay any research person for his time in working specifically for my benefit. Olen R. Gowens,
https://www.genealogy.com/forum/surnames/topics/bruce/2943/ SUSANNA5 BRUCE (THOMAS4, JAMES3, JAMES2, UNKNOWN1) was born Abt. 1805 in , Pittsylvania or Campbell Co., Virginia.She married WILLIAM GOING April 12, 1821 in , Pittsylvania County, Virginia.
Child of SUSANNA BRUCE and WILLIAM GOING is:
24. i. WILLIAM HENRY6 GOWEN, b. February 15, 1822, ,, Virginia; d. , Moniteau County, Missouri.
24.WILLIAM HENRY6 GOWEN (SUSANNA5 BRUCE, THOMAS4, JAMES3, JAMES2, UNKNOWN1) was born February 15, 1822 in ,, Virginia, and died in , Moniteau County, Missouri.He married MARTHA JANE OWEN.She was born May 26, 1832 in , Pittsylvania County, Virginia, and died February 12, 1916 in Florence, Morgan County, Missouri.
Children of WILLIAM GOWEN and MARTHA OWEN are:
i. COLEMAN BRUCE7 GOWEN, b. January 26, 1847, ,, Virginia; d. August 27, 1932.
ii. MARY GOWEN, b. July 26, 1848; d. July 26, 1850.
iii. JAMES THOMAS GOWEN, b. February 09, 1850, ,, Missouri.
iv. SUSAN ANN GOWEN, b. January 18, 1854, ,, Missouri; d. February 1875.
v. WILLIAM HENRY GOWEN, b. March 31, 1855, ,, Missouri; d. August 19, 1875.
vi. ABIGALE FLORENCE GOWEN, b. February 05, 1857, ,, Missouri.
vii. TERRY E. GOWEN, b. July 14, 1859, ,, Missouri; d. 1911.
viii. ELLEN ARABEL GOWEN, b. February 02, 1862; d. May 22, 1945.
ix. LOUELLA THOMAS GOWEN, b. September 02, 1864.
x. VERA LEE GOWEN, b. July 14, 1867.
xi. MARTHA JANE GOWEN, b. October 10, 1869.
xii. LEIF RICHARD GOWEN, b. October 12, 1870.
xiii. JOSEPH SHELBY GOWEN, b. March 12, 1872.