Who was/were the original maker/s of Harley-Davidson motorcycles?

In 1901, two childhood friends, William Harley and Arthur Davidson, started working on building their first motorcycle using the Milwaukee machine shop at the home of their friend, Henry Melk. They were in their twenties at that time. Harley drew up plans for a small engine with a displacement of 7.07 cubic inches and four-inch flywheels. The engine was designed for use in a regular pedal-bicycle frame. They, along with Art Davidson’s brother, Walter Davidson, worked on it over the next two years. Their power-cycle was unable to climb the hills around Milwaukee without pedal assistance. They began working on an improved motorcycle with a bigger engine of 24.74 cubic inches with 9.5 inches flywheels. Joseph Merkel designed an advanced loop-frame pattern for this motorcycle. In 1906, Harley and the Davidson brothers built their first factory on Chestnut Street (later Juneau Avenue). This was one of the companies to survive the Great Depression and become global.