Woolman's writing is distinguished by its plain style, moral sincerity, and deep spiritual conviction. His most celebrated work, "The Journal of John Woolman" (published posthumously in 1774), is regarded as a classic of American spiritual autobiography and was admired by later writers such as Charles Lamb and William Wordsworth. In "Some Considerations on the Keeping of Negroes" (1754), he presented one of the earliest persuasive arguments against slavery by a white American, insisting on the equality of all people before God. Other notable works include "A Plea for the Poor," "A Word of Remembrance and Caution to the Rich," and essays on labor, schools, and the right use of material gifts.
Woolman famously refused to use products of slave labor and worked persistently to persuade fellow Quakers to emancipate their slaves, contributing to the Society of Friends becoming the first American religious body to condemn slaveholding. He died of smallpox in York, England, in 1772, while on a religious mission.