Samuel John Mills Jr., the son of a Congregational minister, was born on 12 April 1783 in present-day Torrington, Connecticut. He attended Williams College, where in 1806 he and four others held the Haystack Prayer Meeting, a key event in the development of American Protestant missions. Mills subsequently co-founded the American Board of Commissioners for Foreign Missions and the American Bible Society. In November 1817 he and Ebenezer Burgess sailed for Africa to purchase land for the American Colonization Society.