Mount Pleasant is a city in Henry County, Iowa, in the United States. As of the 2000 census, the city population was 8,751. It is the county seat of Henry County. It was founded in 1835 by pioneer Presley Saunders. The city is home to Iowa Wesleyan College, which, founded in 1842, ranks as the oldest coeducational college/university west of the Mississippi River. The P.E.O. Sisterhood, an international philanthropic organization for women, was founded on the campus in Mount Pleasant by seven Iowa Wesleyan students. Mount Pleasant is also home to the Midwest Old Threshers Reunion which attracts a crowd numbering over 100,000 admissions annually during an extended five-day weekend which ends on Labor Day. The reunion dates back to 1950 and pays tribute to the agricultural heritage of the American Midwest in an extensive, highly interactive manner, with live-action exhibition-style displays centering on restored mechanical equipment, particularly steam engines, farm tractors, stationary gas engines, antique and classic cars, and the popular narrow-gauge trains and electric trolleys. Country music shows featuring top-name performers, an expansive modern campground with transportation to the main grounds, and an extensive food court and numerous other offerings (run entirely by local churches and nonprofit organizations) are some of the amenities Old Threshers guests enjoy. A meat processing plant operated by West Liberty Foods is located in Mount Pleasant. South of the city is the Mount Pleasant Correctional Facility, a medium-security state prison that houses approximately 960 inmates, predominantly men, and employs 340 staff. The Mount Pleasant Mental Health Institute is also located on the same campus.