The original building was built between 1852 and 1855 and was designed by Philadelphia architect
Samuel Sloan (1815–1884). The north wing was added between 1896 and 1898; the low flanking wings on either side of the exterior staircase were added between 1926 and 1927. These later additions were designed by Lancaster architects
James H. Warner and
C. Emlen Urban, respectively. It is an important example of the
Romanesque Revival style. ==See also==