On the morning of May 26, 1934, a locomotive pulled out of Denver's Union Station bound for Chicago. The Zephyr was unlike any train seen before. Powered by a revolutionary compact diesel engine, it could cover 1,015 miles in a record 15 hours. By the 1940s, fleets of streamliners crisscrossed the country, making the U.S. passenger rail system the envy of the world. But within two decades, the era of these supertrains was over.

[text adapted from kqed.org]