The Market Revolution Websites
This is an interesting little site dedicated to the history of the Erie Canal. It hosts a particularly useful collection of maps and historical images.
The Library of Congress has put together an online exhibit entitled "Religion and the Founding of the American Republic" that includes summaries and images useful in studying the Second Great Awakening.
The National Humanities Center hosts a site on "Divining America: Religion in American History" that contains several useful essays on early nineteenth-century religion.