Charles married his first wife, Almira/Elmira Ratcliff (1856-1891), on March 18, 1880, in Morgan County, Missouri. She is the daughter of Rebecca Comer (1819-1864) and Simon Ratcliff (1818-1897. The location of her burial has not yet been found. Charles married Emma E. Roberts, a widow with children, on January 26, 1892, in Moniteau County, Missouri, and they had three known children, Charles Earl, Treacy Pearl, and Martha.

Thanks to Bette Reese for providing his obituary:

Charles Keller, aged 78 years, passed away at his home south of Tipton, Missouri, Monday night after a short illness. Services were conducted at the grave in the Green Grove cemetery, officiated by Reverend J. B. Bomas of Tipton. Pallbearers were P. J. Class, F. J. Quigley, Garland Wehmeir, Joseph Schmidt, all of Tipton, and Thomas Roach and Oscar Kopp of Fortuna.

Mr. Keller is survived by his widow, Mrs. Maude Keller; three daughters, Mrs. Maude Vaughan of Clarksburg, Missouri, Mrs. Pearl James of California, Missouri, and Mrs. Martha Thompson of Urich, Missouri; two sons, William Keller of the home, and Earl Keller of Urich; one step-daughter, Mrs. Herman Henry (Lillie May) of Clinton, Missouri; and three step-sons, Jacob, Arthur and Jesse Roberts.

Mr. Keller was engaged in farming and was an industrious man.

Thank you to B. Jean Kime Bachman (49834580) for providing the following information.

Lewis, Rose and Helen Keller are the children of Charles Benjamin Keller and his first wife, Almira/Elmira Ratcliff. Their names are on the ground-level stone with that of their father, and four rough individual upright stones surround the ground stone. On the individual stone for Rose, cement was spread on the stone with her name drawn into the cement. The others are most likely the same.