The Journal of John Woolman has been included in Volume I of the Harvard Classics since 1909 and is considered a prominent American spiritual work. John Woolman was an American merchant, journalist, Quaker preacher, and early abolitionist during the colonial era. He advocated against slavery and the slave trade, cruelty to animals, economic injustices and oppression, and conscription. Throughout his life, he kept a journal where he noted his political and religious views and ideas. As it was published posthumously, the diary became famous for the power and clarity of its prose.