5. Streamliners: America's Last Trains

Recalling the stainless steel trains that crisscrossed the country in high style (and at speeds of greater than 100 mph) during the 1930s and '40s. The streamliners -- most notably the Union Pacific's "Little Zip" and the Burlington Railroad's Zephyr -- increased railroad ridership (and profits) dramatically, led to a sleek-is-chic design revolution and even offered a measure of psychological uplift during the Depression.