Thursday, April 13 — The American automobile industry began to take off this month in 1913 — as Henry Ford set up the first moving assembly line in Highland Park, Michigan. Before the assembly line, workers spent over 12 hours building a single Model T. Afterward, it took only 93 minutes. Ultimately, a new car came off the assembly line every 24 seconds, and 15 million were built over the years of production. Prices dropped too. In 1909, a basic Model T roadster cost $825 — by 1925, it was down to $260. Now, U.S. automakers — Ford still among them, of course — manufacture close to $125 billion worth of vehicles annually.