Cavalryman's Portable Telegraph Key and “Chubback” Telegraph Key, photographed in May 2011 at the National Museum of American History in Washington, D.C.

ABRAHAM LINCOLN BIRTHPLACE NATIONAL HISTORICAL PARK
Hodgenville, KY
http://www.nps.gov/abli/index.htm

ABRAHAM LINCOLN LIBRARY AND MUSEUM
Harrogate, TN
http://www.lmunet.edu/museum/

ANTIETAM NATIONAL BATTLEFIELD
Sharpsburg, MD
http://www.nps.gov/ancm/index.htm

FORD'S THEATRE
Washington, DC
http://www.fordstheatre.org/

GETTYSBURG NATIONAL MILITARY PARK
Gettysburg, PA
http://www.nps.gov/gett/index.htm

LINCOLN MEMORIAL
Washington, DC
http://www.nps.gov/linc/index.htm