Harold Mortimer Davison was born on 31. Mar. 1886 at New York City, New York County, New York. He was the son of
Alvah Eugene Davison and
Harriet Louise Selkreg. Harold Mortimer Davison married
Helen Cortelyou DeBaun, daughter of
Jacob A. DeBaun and
Catherine Gerritsen Cortelyou, on 27. Oct. 1910 at Flatbush, Kings County, New York.

Harold Mortimer Davison was shown in the census on 16. Jan. 1920 as the Secretary, Publisher.
Harold Mortimer Davison and
Helen Cortelyou DeBaun appeared on the census of 16. Jan. 1920 at Ridgewood, Bergen County, New Jersey. Harold Mortimer Davison was shown in the census on 7. Apr. 1930 as a Publisher.
Harold Mortimer Davison and
Helen Cortelyou DeBaun appeared on the census of 7. Apr. 1930 at Ridgewood, Bergen County, New Jersey; real estate value 50,000.00. Harold Mortimer Davison was conducts the Davison Publishing Company at Ridgewood, Bergen County, New Jersey. He died in Nov. 1968 at Ridgewood, Bergen County, New Jersey, at age 82.