In 1903, the Pennsylvania Legislature authorized the creation of the Eastern State Institution for the Feeble-Minded and Epileptic and a commission was organized to take into consideration the number and status of the feeble-minded and epileptic persons in the state and determine a placement for construction to care for these residents. This commission discovered 1,146 feeble-minded persons in insane hospitals and 2,627 in almshouses, county-care hospitals, reformatories, and prisons, who were in immediate need of specialized institutional care.
The legislation stated that the buildings would be in two groups, one for the educational and industrial department, and one for the custodial or asylum department. The institution was required to accommodate no fewer than five hundred inmates or patients, with room for additions.
From 1903 to 1908 the first buildings were constructed on 633.913 acres (256.535 ha) of Crab Hill in Spring City, Pennsylvania, Chester County on what was referred to as the lower campus. Out of the first few buildings constructed, 'F' was the Girl's Dining Room, 'G' was the Kitchen and Store Room, 'H', 'I' and 'K' were a Cottage for Girls, 'N' was the Boys' Dining Room, 'P' was the Teacher's Home, 'Q', T', 'U' and 'V' were a Cottage for Boys, 'R' was a School, 'W' was Laundry and Sewing, and 'X' was the Power House.
'P' was used as a temporary Administration building until the institution's opening in 1918 along with the opening of 'L' and 'M' in 1919. In 1921, Whitman and Wilson I and II were constructed along with Penn Hall for employee housing; in 1929, the Assembly building was complete and functioned as the gymnasium and auditorium.
The buildings on lower campus are currently labeled with letters such as 'F', 'I', 'K', 'P', 'Q', 'R', 'N', 'U', 'V', 'T', 'W' and 'X' with names later assigned in the 1960s.
In 1930, the first buildings on the upper campus, otherwise known as the Female Colony, were completed and named Pershing, Buchanan, Audubon and Keystone. Capitol Hall was erected after World War II along with Devon constructed on lower campus. Horizon Hall opened later in 1971.
Lower campus buildings:
Administration, Philadelphia, Quaker, Rockwell, Franklin, Nobel, Union, Vincennes, Tinicum, Industry, Penn, Devon, Mayflower, Limerick, Assembly, Storeroom, Laundry, Whitman, Wilson I, Wilson II, Hershey
Upper campus buildings:
Pershing, Buchanan, Audubon, Keystone, Capitol, Horizon
Power House, Treatment Plant, Director's House, Green House, Dairy Farm