When Youtube was invented, it wasn't clear that a main use of the tool would be time travel. But that's become an important function, as The Travel Film Archive knows well. Digging through the old reels about one city or another, they've gone and digitized them to present us now with an easily streamed trip to San Francisco as it was in 1940. On the eve of America's involvement in the Second War War, as you can hear in the booming voiceover (which might be the best part of the video), it was an optimistic time. So hold on tight and prepare for rare footage of the Key line running on the lower deck of the Bay Bridge and Golden Gate International Exposition structures dotting Treasure Island.