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.
Mrs. Ruth Van Fleet (named in the photo) lived with my grandmother until Van Fleet's death in 1943. The exact date of this image is unknown, but it looks like the women could be working in a munitions factory. So I'd guess it was probably the early '40s. View full size.