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.
Glass negatives from the Detroit Photographic / Detroit Publishing collection at the Library of Congress. These glass plates were the starting point for the millions of colored postcards sold every year by Detroit Publishing in the early years of the 20th century, made using its patented Photochrom process.
In 1939, a year before his death, Detroit Publishing partner William Henry Jackson, whose western plates formed the basis of the company's holdings in its early days, gave the negatives and prints to the Edison Institute (now known as the Henry Ford Museum) in Dearborn, Michigan. In 1949, the Edison Institute gave all of the negatives and many duplicate photographs to the Colorado Historical Society. The Colorado Historical Society transferred most of the negatives and prints for sites east of the Mississippi to the Library of Congress later that year.