Video background from The Library of Congress Webcasts site:

"Cartographers during the U.S. Civil War invented new techniques and mapped the country—both Union and Confederate territories—more accurately than ever before in the nation's history. The morning session of this day-long conference included presentations on 'Hidden Patterns of the Civil War,' 'Mapping the Strength of the Rebellion' and 'We Were Profoundly Ignorant of Our Country: The Struggle to Provide Accurate Maps During the U.S. Civil War.'"

For the video of the afternoon session of this conference, click here.