Samuel is listed as a widower in the 1880 census of California, Moniteau County, MO. Missouri births show a Samuel Evan Hoge as the father of two children and the mother was Julia Rayhill. They were born in California, Moniteau County, MO in the 1880's. It seems likely Samuel had remarried.
The 1900 census of Springfield, Sangamon County, IL shows a Samuel Hoge, born Oct 1832 in Kentucky, and Julia, born Jan 1853 in Illinois. They were married 19 years. The children correspond to the children born in MO.
The Illinois index of deaths shows a Samuel E. Hoge who died on the same date in 1902. His death record may or may not have his parents' names. I suggest getting it anyway.
This Samuel E. Hoge applied for a Civil War pension as did his widow Julia: Appl 1,281,346 Widow Appl 1,180,001. He served as a 2nd LT in Company G, in what seems to be a Missouri regiment. It doesn't look like they actually received a pension. Nevertheless his pension file may have some helpful data on them since the application procedure is the same whether they got the pension or not.
You can get a copy of his pension from the National Archives in Washington, DC for $75. While a bit pricey and the genealogical data it contains is uncertain, it may have some of what you are looking for. As I understand all the pensions will eventually be online, but I don't know the timeline. Some are already available online at Footnote.com for a fee.
I didn't find an older brother by the name of Stewart for Samuel. I did find a Stewart Hoge who married an Elizabeth and they had a daughter Eva who seemed to fit the bill. He was born in 1837 in Pennsylvania. He too lived in MO and IL. The 1900, 1910 and 1920 census show him living in Macomb, McDonough County, IL.