The One-Room School Strasburg, Colorado's well-preserved Living Springs School was built in 1891; the 15 differences between the images were created in 2018. Copyright © 2002-2024 All-Star Puzzles All rights reserved

Credit line: Gates Frontiers Fund Colorado Collection within the Carol M. Highsmith Archive, Library of Congress, Prints and Photographs Division.    To view the original image: http://www.loc.gov/pictures/collection/highsm/item/2017885366/