James Callaghan was born in September 1920, and lived at 199 Larchmont Avenue. He attended Elementary School at the "little convent" at St. Augustine's School. He was admitted to Iona Preparatory School in September 1929 after completing the third grade at St. Augustine's. He graduated from Iona Preparatory School in June 1937. Across his transcript from Iona is handwritten (in large letters) "RIP In Action".

He was the son of James G. Callaghan and Mary A. Callaghan. James G. Callaghan died of a heart attack in Grand Central Station around 1938-39, when James was about 19 years old. Mary Callaghan died around 1956-57 She moved to Locust Avenue in New Rochelle after the death of her husband.

"Bud" was also the brother of Louise Callaghan Wheeler, Jane Callaghan and Helen Callaghan Curran. Louise was the eldest, then Bud and Jane, and Helen was the youngest.