The document summarizes the history of bicycles and motorcycles from their earliest origins in the late 18th century to developments in the 20th century. Some of the key events and innovations discussed include the invention of the velocipede in 1817 which was one of the first two-wheeled riding machines, Kirkpatrick Macmillan's invention of the first pedal-driven bicycle in 1839, the introduction of the penny-farthing style bicycle in 1870, and the safer chain-driven safety bicycle design introduced in the 1880s which resembled modern bicycles. The document also notes how bicycles grew increasingly popular in the late 19th century as designs improved, leading to their mass production and social impacts including changes in women