what county is canonsburg, pa in?
Canonsburg is a town in Washington County, Pennsylvania, 18 miles (29 km) southwest of Pittsburgh. Canonsburg was laid out by Colonel John Canon in 1789 and incorporated in 1802. The town is in a rich coal district, and most of the town's work force once worked in local steel mills or coal mines. Canonsburg's population in 1910, including South Canonsburg, which was annexed in 1911, was 5,588; in 1920 it was 10,632; and in 1940 it was 12,599.