Emmett was the son of Charles and Dolly (Dygert) DeCamp. Children by his first marriage to Margaret Basler were Warren Thadius and Hiram A. DeCamp. The children by his second marriage to Ann Eliza Howe were Annetta, Marshall, Rhoda, Silas Augustus, Grotus Lafayette, Emily, Nelly, Norman, Charles Emmett, Nancy, Ida, Adeline, Lydia Josie, Hetta May, and Annice.

Emmett's obituary reads: "On Thursday morning of last week occurred the death of E. W. DeCamp, one of the oldest residents of this part of the county (Dallas Co. Iowa). He was making his home at the time with his son, Warren DeCamp of Kenedy. He was 85 years and 6 months old.

Mr DeCamp was a man of unusual vigor and spryness for one of his advanced age, and was in good health until last fall when his stomach seemed to fail him and he rapidly declined in health. The death was probably more the result of old age than of any specific disease, a general wearing out of the human machinery after years of toil and use. Mr. DeCamp was a resident of Dallas county for many years. The farm which is now the John Walker place was for twenty-five or thirty years his home. He also lived for a time in Kansas, Missouri and Texas, in the latter of which states he still owned land. Mr. DeCamp was the father of a numerous family; most of whom are well known to Adel and Dallas county people.... (goes on speaking about some of his children)...... The funeral was held Friday afternoon at the Panther Creek U. B. church, conducted by Dr. Geo. Miller of Des Moines, a friend of many years of the deceased brother. Dr. Miller was formerly a presiding elder in that church and grew well acquainted with Mr. DeCamp through the latter's activities in church work. The burial was made in Panther Creek cemetery."