(AP) — Hugh Ambrose, who wrote the World War II history "The Pacific" after years of researching for his father, the renowned historian Stephen Ambrose, has died at age 48. Ambrose began his career while he was in graduate school at the University of Montana in the mid-1990s by helping his father research books such as "Undaunted Courage," the story of the Lewis and Clark expedition. Ambrose continued to work on "The Pacific" and raise money for the National World War II Museum after the move to Helena.