On November 29, 1886, the Lycoming County court incorporated the villages of Rocktown, Billman, and vicinities as the borough of South Williamsport.

The lands of the West Branch Susquehanna River valley were then chiefly occupied by the Munsee clan or phratry of the Lenape, and were under the nominal control of the Five (later Six) Nations of the Iroquois.

The British purchased land from the Iroquois in the Treaty of Fort Stanwix of 1768, opening what is now Lycoming County to settlement.

The first settler in what is now South Williamsport is believed to have been Aaron Hagerman, a transplanted Hollander, who is thought to have arrived shortly after the end of the American Revolutionary War.

Another early entrepreneur, Jacob Weiss, gave the village a push toward borough status by purchasing a tract of 40 acres and laying out town lots.

Weiss also established a brickyard near McDonough’s tavern and for many years operated an oil mill and a gristmill.

Planing mills and woodworking factories of all types reached a peak of activity during the logging boom of the post-Civil War years of the last century.

The industry gradually declined in the 1890s when the surrounding hills were finally stripped of saleable lumber and the logging crews moved west.

The area is reforested with second-growth timber, providing scenic beauty as well as woodland recreational opportunities.

The 2000 census counted 6,412 residents and today, 1,534 students are enrolled in three South Williamsport Area Schools Central Elementary (K-4) is on West Mountain Ave. Rommelt Elementary (5-6) is on West Central Ave. South Williamsport Area Jr./Sr.

Major ancestry groups reported by South Williamsport residents include: German - 37%, Irish - 12%, Italian - 10%, English - 8%, Pennsylvania Dutch - 5% Polish - 4%, French (except Basque) - 3%, Welsh - 1%, Scots-Irish - 1%, Scottish - 1%, Swedish - 1%, Swiss - 1%