Guess the year it was taken.

Five photos from public archives. Slide to the year you think each one was taken. Each round starts at 100 points and loses one for every year you're off. A full game is out of 500.

The first photos are full of clues like cars, clothes and shop signs. By the last round you're dating rivers and treetops.

Photos load live from the Library of Congress, with Wikimedia Commons as a backup.