I thought he might have had a hand amputated ... maybe not. And even if so, it may have nothing to do with the Civil War. 1905 ? So maybe aged about 30 in 1865. The hat suggests a Southerner rather than, say New York or Massachusetts. ( Yes, I'm fishing for hints).
I'll try Everton Conger (died 1918, Montana)
“The honest man, tho' e'er sae poor,
Is king o' men for a' that” Robert Burns