Strong was born on November 14, 1885, in a "two-room parsonage" in Friend, Nebraska, the "Middle West," to parents who were middle class liberals active in the Congregational Church and missionary work. She lived with her family from 1887 to 1891 in Mount Vernon, Ohio and in Cincinnati beginning in 1891. Her father, Sydney Dix Strong, was a Social Gospel minister in the Congregational Church, active in missionary work, and dedicated pacifist. Strong worked quickly through grammar and high school, and then studied languages in Europe.