Most of the photos on this site were extracted from reference images (high-resolution tiffs, 20 to 200 megabytes in size) from the Library of Congress research archive. (To query the database click here.) Many were digitized by LOC contractors using a Sinar studio back. They are adjusted by your webmaster for contrast and color in Photoshop before being downsized and turned into the jpegs you see here.
May 1864. "Rappahannock River, Virginia. Ruins of bridge at Germanna Ford, where the troops under General Grant crossed May 4." Wet plate glass negative by Timothy O'Sullivan. View full size. (Though the caption on the negative sleeve says Rappahannock, Germanna Ford seems to have been on the Rapidan River.)