The Borough of Lewistown was incorporated in 1795. It is named for William Lewis, a state assemblyman who helped to secure its status as the county seat of Mifflin county. Mr. Lewis also served as an attorney and a federal judge, and was an ardent opponent of slavery.
Lewistown's early major industries included iron manufacturing and metalworking. Companies such as the Glamorgan Iron Works, Logan Foundry, Lewistown Foundry and Mann Axe Works provided many jobs. Transportation was another important local economic pillar in the 1800s, with the opening of the Pennsylvania Canal through Lewistown in 1829, followed by the arrival of the Pennsylvania Railroad in 1849. Smaller industries also thrived, included flour milling, lumber and brick making, construction, boat building, pottery manufacture, brewing and distilling, mercantile establishments and the keeping of hotels and inns.
The earliest structures in the borough were constructed of logs. The first half of the nineteenth century saw a great rise in the construction of stately brick dwellings, storefronts and other buildings. This continued into the 1900s. Many of these beautiful buildings still stand today, with some dating to the 1830s, 40s and 50s, including the historic 1843 Mifflin County Courthouse.