William S. Harley and his neighbor Arthur Davidson built their first motor-driven bicycle in 1903 in a shed in Milwaukee. Some 111 years later the company they founded (No. 433 on the Fortune 500) is still headquartered just a block away from that original shed–but a world away in scale. Last year 7,400 employees built some 260,000 of Harley’s (HOG) iconic hogs, generating $5.9 billion in global sales. This factory, in York, Pa., assembles more than 60% of the company’s motorcycles. You can almost hear the roar of the engine.