http://www.volunteeringinamerica.gov/

This website, from the federal Corporation for National and Community Service, offers the most comprehensive research on U.S. volunteering ever assembled. Research findings on the site include volunteer rates, economic impact, and information on “voluntourism” (long-distance volunteering), with breakdowns by state, region, and major city as well as national data. The site also includes links to volunteer opportunities, tools for volunteer recruitment and retention, and other recent government studies of volunteerism among college students and others.