Dec. 17: The first Clean Air Act passes Congress on this date in 1963

By the time Congress passed the first Clean Air Act on this date in 1963, the phrase "killer smog" was already well-known, thanks to towns like Donora, Pa., where a cloud of smog from the nearby zinc plant settled over the town for five days in 1948, killing 20 and sickening 6,000. Major cities like Los Angeles were frequently bathed in a brown cloud, and a year earlier Rachel Carson's "Silent Spring" had set off a wave of public outcry over the worsening environment. Within two years, the first federal pollution standards for cars would be tacked onto the act, even as California officials were approving the first pollution control devices for vehicles. Today, on a poor air quality day in Los Angeles the exhaust coming from the tailpipe of several new vehicles will be cleaner than the air they suck in — while China re-learns America's lessons the hard way.