Henry Warner Kloepfer was born in Roseville, Ohio on 25th February, 1913. He graduated from Ohio University in 1934. Six years later he was awarded his PhD in human genetics. He married Ruth Elizabeth McCoy and the couple had four children (Jean, Karol, Ruth and John).

Kloepfer was associate Professor of Human Genetics at Tulane University Medical School. His research included researching the identification and description of specific major genes.

When Lee Harvey Oswald was arrested he had written the names Warner and Ruth Kloepfer in his address book. Ruth Kloepter, the clerk of the New Orleans Quaker Meeting, was introduced to Oswald by Ruth Paine in the summer of 1963. Paine asked the Russian-speaking Kloepfer to visit Marina Oswald.

Henry Warner Kloepfer died in New Orleans on 27th March 1982.