[1] Mary Patterson Elkinton was born in 1857 to a prominent Quaker family in Philadelphia.
Their only child died in infancy, but they adopted Nitobe's nephew, Yoshio, and a female relative Kotoko.
[2][3] Living in Japan, which she considered her home, she contributed to educational reform, worked to improve US-Japan relations, advocated internationalism and helped to establish several schools.
When her husband served in the League of Nations at Geneva she was active in international circles.
After they returned to Tokyo in the late 1920s, she found Japanese militarism in conflict with her Quakerism.