His parents divorced when he was a small boy.

In 1930 Delbert is recorded as having lived both with his mother and stepfather Alvah Davis at #4, 408 South Sanborn Street, Mitchell, Davison County, South Dakota, and with his father, grandmother Henrietta Knuppel and aunt Bertha Knuppel at 211 East Eighth Street, Morris, Stevens County, Minnesota. Presumably he alternated between parents at this time.

In 1935 he lived in Morris, Stevens County, Minnesota, presumably in his father's household at 508 Montano Avenue, which included the same other family members as in 1930. In 1940 he is recorded as living both with the family at that address and on his own at the YMCA at 30 South 9th Street in Minneapolis, Hennepin County, Minnesota, where he worked as a beautician.

Later in 1940 the family was all living together in Minneapolis again, now at 2933 34th Avenue S. Delbert's occupation was given as clerk.

Delbert's Social Security card was issued in Minnesota.

Delbert served in the U.S. Army during World War II, enlisting March 22, 1943 and released February 25, 1946.

In 1946 Delbert was living with his father and stepmother Viva at 2604 4th, Des Moines, Iowa. He was in the US Army at the time.

At some point Delbert married and later divorced. He may have been the Delbert Le Roy Knuppel who married, May 17, 1946 in Seattle, King County, Washington, Ida Danichek. She was born — –, 19— in —, the daughter of — — and — (—) —.

About 1947 he became a purser for Pan American Airways.

In 1948 he was living with his father, stepmother, and aunt Bertha at 166 Stanley, Redwood City, California. Delbert's occupation was given as flight steward with Pan American Airways.

From at least 1961 through 1968 Delbert was living in San Francisco, California. He was residing with his aunt Bertha at 666 Guerrero in 1961. From 1962 through 1968 his home was at 325 Mangels Avenue. Bertha lived with him there from 1963 through 1968. Delbert's occupation was given as purser at the International Airport in 1961, and as purser for Pan American Airways from 1963 through 1968.

In 1980 Delbert lived at 150 Park Lane, Sonoma, Sonoma County, California.

Delbert's last Social Security benefit was received in Santa Rosa, Sonoma County, California 95405. He died from cardiovascular collapse following coronary bypass surgery on June 23, 1980, aged 59, at Mt. Zion Hospital, 1600 Divisadero Street, San Francisco, California. After cremation on June 26, 1980 at Cypress Lawn Memorial Park, Colma, California, informal outdoor services were held at 2:00 P.M. on Friday, June 27, 1980 outside the Hall of Flowers in Golden Gate Park, San Francisco.