Possibly much more than you want, but here is his life after civil war.

Gray, http://www.rootsweb.com/~arpulask/Col.MrsOCGray.html, returned to Princeton Female Academy as headmaster, then helped reopen St Johns' College in Little Rock in 1867, served seven years, last three as president, then to Arkansas Industrial University as Math and 1st chair Civil Engineer professor (wife had 1st chair for art) till 1885 when all professors were relieved, he returning as one of three invited back in 1888 as chairman of math til 1895, then superintendent of Arkansas School for the Blind, Little Rock, a controversy for two years, spent at Spears-Langford in Searcy, back to ASB till his death 1905.

Univ Ark dedicated GRAY HALL to him in 1906, removed 1966 for Mullins Library.

He spent 45 of his 50 teaching years in Arkansas, with his former student, Geo Burton Rose, speaking at his funeral were hundreds attended, to wit: http://ftp.rootsweb.com/pub/usgenweb/me/lincoln/newspapers/tributet3nw.txt