  Coinciding with his marriage in 1841 to Sarah Mabitt Elston, Crummell's career as a public thinker began in earnest. His prominence as a young intellectual earned him a spot as keynote speaker at the anti-slavery New York State Convention of Negroes when it met in Albany in 1840. Despite race-based resistance, he successfully trained for the priesthood, becoming an Episcopal priest later that same decade. He studied moral philosophy at Cambridge University under William Whewell, whose view of moral reasoning as an intuition of necessary moral truths clearly influenced Crummell's own thought. After taking his bachelor's degree at Queen's College at Cambridge he resumed his avid participation in the anti-slavery movement. He subsequently went to Liberia taking a position as a professor of English and moral philosophy at Liberia College. His time there was difficult, owing to personal challenges and political opposition, leading him to return to the States after the Civil War. His first book was published in New York, entitled The Future of Africa (1862); in it he solidified much of his early thinking on morality and language. Two subsequent books, The Greatness of Christ (1882) and Africa and America (1891), reflected his more mature thought on agency and moral change.