Mechanicsburg is a borough in Cumberland County, Pennsylvania, USA, eight miles (13 km) west of Harrisburg. It is part of the Harrisburg–Carlisle Metropolitan Statistical Area. Mechanicsburg was settled in 1806 and incorporated as a borough on April 12, 1828. It is in a rich agricultural region known as the Cumberland Valley, a broad zone between South Mountain and the ridge-and-valley Appalachians. In 1900, 3,841 people lived here; in 1910, 4,469, which increased to 5,709 in 1940. As of the 2000 census, the borough population was 9,042. Mechanicsburg is home of Jubilee Day, the largest and longest-running one-day street fair on the east coast. It is estimated as many as 60,000 people attend Jubilee Day annually. The borough is home to Mechanicsburg Area Senior High School and just outside the borough is Cumberland Valley High School.