Edgar G. Whalen was the son of George Riley Whalen and Lucy Ann (née Thornton) Whalen. He was most likely born in Tioga County, New York in October 1859. His parents were both natives of Owego, Tioga County, New York.

Edgar's name is also listed as George E. Whalen in some US Census records. It's possible that his given name was George Edgar Whalen, but he chose to go by his middle name (Edgar) since his father was also named George.

Edgar's father was the son of David Whalen and Lucy/Sally (née Guiles) Whalen. Edgar's mother was the daughter of Silas Thornton and Susan (née Sager) Thornton.

Edgar's aunt was Dora (née Thornton) Whalen. She was another daughter of Silas and Susan Thornton. She married Jeremiah "Jerry" Whalen (1846-1913). It is currently unclear how Jeremiah was related to Edgar's father, George. It's possible that they might have been cousins?

Edgar had the following known siblings:
Theodore Whalen
Albert Whalen
Isabelle "Belle" (née Whalen) Wright

Edgar married Clara E. (née Zimmer) in about 1880. She was the daughter of Alvah and Sarah Zimmer.

Edgar and Clara had the following known children:
Emma P. Whalen m. John E. Howard
Ida Mae Whalen m. William C. Howard

1860 Census: Owego, Tioga, NY
George Whalen 35
Lucy Whalen 20
Theodore Whalen 2
Geo E Whalen 1 [Edgar]
David Whalen 68

1870 Census: Ulster, Bradford, PA
Geo Whalan, 37
Lucy Whalan, 31
Theodore Whalan, 12
Edger Whalan, 10
Albert Whalan, 9
Isabell Whalan, 7
Susan Thornton, 53

1875 Census: Nichols, Tioga, NY
George R Whaling, 40, Head
Lucy Whaling, 36, Wife
Theodore Whaling, 16, Son
Edgar Whaling, 15, Son
Albert Whaling, 13, Son
Isabell Whaling, 10, Daughter

1880 Census: Candor, Tioga, NY
George Whalen 46 Self (Head)
Lucy Ann Whalen, 42 Wife
Edward Whalen, 20 Son [Edgar]
Albert Whalen, 19 Son

1900 Census: Spencer, Tioga, NY
Edgar G Whalen 40 Head
Clara E Whalen 33 Wife

1905 Census: Candor, Tioga, NY
George E Whalen 46 [Edgar]
Clarra H Whalen 37
Ida M Whalen 21

1915 Census: Spencer, Tioga, NY
Edward G Whalen 55 Head [Edgar]
Clara E Whalen 48 Wife

1920 Census: Spencer, Tioga, NY
Edgar Whalen 60 Head
Clara Whalen 53 Wife

1925 Census: Erin, Chemung, NY
Ed Whalen 63 Head
Clara Whalen 58 Wife

1930 Census: Erin, Chemung, NY
Edgar Whalen 69 Head
Edith Wood 54 Servant