Massachusetts Abraham Lincoln Bicentennial Commission
http://malincoln.org

The Civil War Round Table of Greater Boston
http://www.cwrtgb.com

The Military Historical Society of Massachusetts
http://www.mhsm.org

The U.S. National Archives and Records Administration
http://www.archives.gov

13th Mass.org
http://13thmass.org/1862/pope.html

Massachusetts Civil War Research Center
http://www.massachusettscivilwar.com