I found an F. M. Brown, Pvt., Co. F, 18th Tennesse Cavalry in Tennesseans in the Civil War, Part 2.
I also did an Ancestry.com and Google search and came up with the following composite:
Fenton M. Brown, Pvt., Co. F, 18th Tennessee Cavalry, was a farmer, age 53, born in Tennessee, 1860 census with two children at home, James, age 17, and Eliza, age 11, residing in District 6, Cumberland, Tennessee, Crossville Post Office, father was born in Virginia, mother in North Carolina, in 1870 his household consisting of Francis, female, age 39, keeping house; Fenton, male, age 2 and Lavana [sp?], female, age 4/2?, residing in District 9, Scott Co., Tenn., Huntsville PO, in 1880 the houselhold consisted of Francis, son Washington, age 13, daughter Lavarna, age 10, and son Levitrnitt [sp?], age 7, residing in Brimstone, Scott Co., still listed as Farmer, died 1882
David Carlson [dcarlson@surfsouth.com], on Fri Sep 20 18, 1996, on the Knox Co. TNGenWeb Query page, http://www.knoxcotn.org/knoxqryarchive/knoxsep96.html, asked:
Seeking any and all info on Fenton Jackson Brown (1830?- ) m. 1847 in Crossville, TN to Elizabeth Baker, possibly of VA. Was Fenton M. Brown his father? Who were the parents of Elizabeth Baker. Also need info on David Weaver who married Mareca Jane Varner on March 8, 1831 in Knoxville, TN. The children of both these families married and moved to Washington state in 1888
Interestingly, the family in 1910 were residing in my hometown of Everett, Snohomish Co., Washington.
George Martin
Sparks, NV