Dr. Joseph Priestley, the discoverer of oxygen, was a Unitarian minister who immigrated to the U.S. with the help of Benjamin Franklin after his home, church and lab were destroyed by a mob in England because of his pro-American and French Revolution advocacy and his Unitarian religious views. Once here, he continued his religious and political discourse joining Thomas Jefferson and James Madison, thus running afoul of the Federalists and the Alien and Sedition Acts. He became a target of venomous political attacks after recommending that others should immigrate to America.