Harley-Davidson isn't the oldest American marque – that distinction goes to Hendee/Indian – but it's the only one that has been in continual operation since its inception in 1903 up through ...

In fact, the manufacturer had an entire line of head-themed engines, including the Knucklehead, Panhead, and Shovelhead, with some featuring in the rarest Harley-Davidson motorcycles ever built.

While you may be able to name a dozen prominent American manufacturers, few produce a product as legendary and iconic as Harley-Davidson, Inc. With more than a century of motorcycle building ...