Looking for Parents of Littleton Morgan Tough of Baltimore Maryland

I am trying to locate the family of my great-grandfather Littleton M. Tough of Baltimore Md. (who was born in Feb 1847 and I believe died in 1911). He was married in about 1880 to Elizabeth "Lizzie" Bevan (sometimes spelled Beaven). They had 3 children: Littleton Morgan Tough Jr. (1881-?), Elizabeth "Elsie" Bevan Tough Schauffler (1884-1935) and Fred B. Tough (1885-).

I have found information about his sister Jane S. Tough and mother "Ascha" Tough in the 1870 and 1880 census for Baltimore (she was a widow by then)--but haven't been able to get more information on his mother or his father. Any help would be welcome.