Fountain pen manufacturing became one of Janesville's most lucrative enterprises. Most important in this sphere was the formation and gradual expansion of the Parker Pens Company. In 1891, George Parker incorporated the Parker Pens Company and began producing quality fountain pens - beginning with the "Lucky Curve" fountain pen. Over the next two decades, the company flourished and expanded, moving to larger accommodations on several occasions.
by 1920, the Parker Pens factory was built at East Court and Division streets. The factory was expanded in 1930 when employment reached over 700 workers. By 1950, the company had offices in Canada, France, England, Africa, and Scandinavia, and Parker Pens rivaled the best in the world.
At its peak, the Parker Pens company had a 212,000 square foot factory with over 2,000 workers, making it one of the largest employers in the county. By the 1980s, the production of cheap ball point pens and disposable ink pens had a negative impact on Parker Pens. Eventually the company was sold to overseas interests and the factory was shut down. However, Parker Pens are still used today for ceremonial bill and treaty signings at the White House.