High Quality Content by WIKIPEDIA articles! Chambersburg is a borough in the South Central region of Pennsylvania, United States. It is 13 miles (21 km) miles north of Maryland and the Mason-Dixon line and 52 miles (84 km) southwest of Harrisburg in the Cumberland Valley, which is part of the Great Appalachian Valley. Chambersburg is the county seat of Franklin County. The United States Census Bureau estimates the population within the borough limits as of July 1, 2008, as 18,302. When combined with the surrounding Greene, Hamilton, and Guilford Townships, the population of Greater Chambersburg is 52,273. Chambersburg is at the core of the Chambersburg Micropolitan Statistical Area which includes surrounding Franklin County. The population of the Chambersburg Micropolitan Area in 2008 was 143,495.