After the New Harmony utopian community dissolved in 1827, Owen traveled in Europe before returning to the United States in 1829. During this period Owen wrote "Moral Physiology; or, A Brief and Plain Treatise on the Population Question" (1830), a controversial pamphlet on the topic of population control. It was one of the first books in the United States to advocate birth control, along with Dr. Charles Knowlton's "Fruits of Philosophy". Knowlton and Owen were contemporaries and apparently knew each other. Content from Knowlton's book appears in Owen's, and the second edition of Knowlton's book includes some of Owen's content.