In protest to the Townshend Acts, Dickinson published "Letters from a Farmer in Pennsylvania". First published in the "Pennsylvania Chronicle", Dickinson's letters were re-printed by numerous other newspapers and became one of the most influential American political documents prior to the American Revolution. Dickinson argued that Parliament had the right to regulate commerce, but lacked the right to levy duties for revenue. Dickinson further warned that if the colonies acquiesced to the Townshend Acts, Parliament would lay further taxes on the colonies in the future. After publishing these letters, he was elected in 1768 to the American Philosophical Society as a member.