Scroll through these four images below and move the handle bar left and right to compare these aerial photos from 1922 with the real estate maps of the day. The aerial image is a mosaic constructed from 215 photos taken from an altitude of 10,000 feet. To capture these images, the U.S. Army Air Service spent more than two hours circling the area in plane traveling about 100 miles an hour. The map on the right is a 1919 Baist's real estate atlas of surveys of Washington. Have fun!    

Source: Library of Congress: 1922 DC aerial view | Baist book of DC map surveys     *images might not appear on some browsers