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.
Harris & Ewing black-and-white photographs imaged directly from large-format glass negatives. The photographs were made by the prominent Washington, D.C., photo studio founded in 1905 by George Harris and Martha Ewing. Harris & Ewing glass plates currently residing in the Library of Congress Prints & Photographs Collection.