Samuel Billings Capen was born on December 12, 1842 in Boston. Capen would graduate from Boston English High School in 1858 and would eventually become a carpet dealer under the name Torrey, Bright & Capen. Capen would also double as an active member of church and civic affairs which eventually led him to Sunday School work at the Central Congregational Church in Jamaica Plain. Samuel married his wife Helen in 1869. Capen would eventually receive his honorary A.M. degree from Dartmouth College and an L.L.D. from Oberlin College and Middlebury College.

Samuel would become heavily involved in a number of different organizations starting in 1882 when he became the president of the Congregational Sunday School and Publishing Society. He was able to reorganize the group's finances and set them up for future success. He also served on the Boston School Committee from 1888 to 1893 and was the chairman in 1893. Other organizations he was a part of include the Boston City Missionary Society, United Society of Christian Endeavor, Boston Chamber of Commerce, North American Civic League for Immigrants, Watch and Ward Society, Massachusetts Bible Society, Mayflower Society, Boston Municipal League and more.

The American Board of Commissioners for Foreign Missions would also benefit from Capen’s services when he became president in 1899. He was a part of the Haystack Prayer Meeting in 1906 and would eventually travel to Asia as the head of the ABCFM and as a member of the World peace Foundation. He died of pneumonia in Shanghai, China on January 29, 1914.