The first Harley Davidson motorcycle was built in the backyard of the family home of William Davidson in 1903. Today, their headquarters stand on the same site. In 1994, the property took it's place on the National Register of Historic Places. The address is 3700 West Juneau Avenue in Milwaukee, Wisconsin. The corporate headquarters take up over four city blocks and almost 500,000 square feet. The lobby of the Milwaukee headquarters is open to visitors during business hours.