Groundbreaking took place in 1872, and the buildings were not opened until November 18, 1880. Even then Richardson's plan was not complete. The State Legislature did not appropriate enough money to build the five ward buildings west of the administration building.
With the local population growing rapidly in the 1880s, the need for a larger facility was acute. Funds for construction of the remaining ward buildings were appropriated in the early 1890s, and the Board of Managers at the state Hospital insisted that Richardson's plan be carried through. The remaining ward buildings were constructed between 1891 and 1895. Richardson died in 1886, and thus never saw the completion of the project.

In 1973, the State Hospital buildings designed by Richardson were placed on the National Register of Historic Places of the National Park Service, and in 1986, the buildings were named a National Historic Landmark.
The three easternmost ward buildings were demolished in 1969. In 1974 use of the remaining seven ward buildings for patient care was discontinued. The hospital's administration continued to occupy the Twin-Tower administration building until 1994.

From "Niagara Frontier Landmarks", by Jason Aronoff, 1977