In 1834, after completing the economic series, Harriet Martineau paid a long visit to the United States during which she visited a great many people, some little known, others as famous as James Madison, the former US president, at his home at Montpelier. She also met numerous abolitionists in Boston and studied the emerging schools for the education of girls. Her support of abolitionism, then widely unpopular across the U.S., caused controversy, which her publication, soon after her return, of "Society in America" (1837) and "How to Observe Morals and Manners" (1838), only fuelled. The two books are considered significant contributions to the then-emerging field of sociology.