[1] Ordained into the Unitarian church he first became an active minister at Louisville, Kentucky, then a slave state, and soon threw himself into the national movement for the abolition of slavery.

"[3] In 1840, he returned to Boston where he and his friends established (1841) the Church of the Disciples which brought together a body of people to apply the Christian religion to social problems of the day.

[citation needed] Clarke edited the Western Messenger, a magazine intended to carry to readers in the Mississippi Valley simple statements of liberal religion and what were then the most radical appeals to national duty and the abolition of slavery.

[2] Copies of this magazine are now valued by collectors for containing the earliest printed poems of Ralph Waldo Emerson, a personal friend and a distant cousin.

This never came to pass, instead the land was offered to President Abraham Lincoln during the American Civil War; the Second Massachusetts Regiment used it for training and named it "Camp Andrew".

After hearing the song "John Brown's Body", he suggested that Mrs. Howe write new lyrics; the result was "Battle Hymn of the Republic".

In a statement published posthumously, Clarke had written, "one of the most important of the reforms proposed at the present time is that which shall give suffrage to women.

Many of Clarke's earlier published writings addressed the immediate need of establishing a larger theory of religion than that espoused by people who were still under the influence of Calvinism.