American motorcycle manufacturer founded in 1903. Harley-Davidson is noted for a style of customization that gave rise to the chopper motorcycle style.
In 1901, 20 year-old William S. Harley drew up plans for a small engine, designed for use in a regular pedal-bicycle frame. Over the next two years, he and his childhood friend Arthur Davidson worked on their motor-bicycle. Upon testing their power-cycle, Harley and the Davidson brothers found it unable to climb the hills around Milwaukee without pedal assistance, and they wrote off their first motor-bicycle as a valuable learning experiment.
The three began work on a new and improved machine with an engine. The bigger engine and loop-frame design took it out of the motorized bicycle category and marked the path to future motorcycle designs. The prototype of the new loop-frame Harley-Davidson was assembled in a 3.0 × 4.6 meters shed in the Davidson family backyard. Most of the major parts, however, were made elsewhere.