William Tim O'Brien was born on October 1, 1946, in Austin, Minnesota. His father sold insurance and his mother was a teacher. Both of O'Brien's parents served in the military during World War II. O'Brien and his family lived in Austin, Minnesota, for ten years, then moved to Worthington, Minnesota, where O'Brien spent the rest of his childhood and adolescence. He enrolled in 1964 at Macalester College in St. Paul, Minnesota.

In 1968, just two weeks after graduating Phi Beta Kappa from Macalester and while preparing to enter Harvard graduate school, O'Brien received his draft notice. Although he was opposed to the war, he found himself in August 1968 assigned to an infantry unit in the army on his way to Vietnam.

O'Brien's Vietnam experience was life changing. Upon his return to the United States, he enrolled at Harvard as a doctoral student in government. During this time, he wrote for...