(November 29, 2014) One of the comforts most Americans take for granted while driving was displayed for the first time this month (Nov. 4) in 1939 at the 40th Automobile Show in Chicago.

The Packard Motor Car Company unveiled the first U.S. car with air-conditioning. The cooling and heating equipment in the Packard was located behind the rear seat in the trunk. Treated air reached the passenger compartment through ducts mounted between the seats and the rear window.

The "Weather Conditioner" was a $279 option that required the Packard One-Eighty to visit a second factory for installation, since the unit connected to the engine and took up half the trunk space. Packard pitched it as not just for comfort but privacy, since riders could finally arrive without having the windows down.

The option didn't sell well — there was no way to moderate the air from the unit — and Packard dropped it after 1942.

Air-conditioning did not become a widely available, affordable option until well after World War II. Starting in 1969, the majority of new cars and trucks made in the U.S. have been equipped with air-conditioning.