On February 22, 1802, Governor Thomas McKean signed an Act of the Pennsylvania General Assembly that incorporated the Borough of Canonsburg. It was just a coincidence that the date is George Washington’s Birthday. The town on the stage road between Washington, the county seat, and Pittsburgh was about fifteen years old. The main street ran up a hill with a steep grade. The founder, developer, and proprietor was John Canon, whose flour and saw mill was at the foot of the hill.
Early in its history, Canonsburg became a market town. A market house stood at the intersection of what we now know as Central Avenue and College Street. The main street, Central Avenue (known at various times as Market, Main, and Front Street), was lined with shops, taverns, and artisans’ workshops.

An academy was founded in Canonsburg in 1791, and in 1802 it was incorporated as Jefferson College. By 1840, the college had become the economic base of the town and it was by far the largest college in the state and was one of the largest colleges in the country. In the decades before the Civil War, about ten percent of the college students were sons of Southern planters, who carried big knives and heavy wallets.

The Civil War, lack of alumni support, and ill-conceived scholarship schemes drove Jefferson and Washington Colleges to merge in 1865. For three years, the upper classes and the commencement activities were in Canonsburg, but in 1868 the college was united on the Washington campus.