They originally intended the facility to be based on the Worcester State Hospital in Massachusetts and sited on 105 acres (42 ha) of land purchased from former Governor Leonard J. Farwell (1852-1854).

Plans fell apart in 1855 due to allegations of corruption and waste and the Legislature repealed the law after $27,000 ($915,600 today) had already been spent on the project.

[3] The legislature acted again on the plan in 1857 and a Board of Commissioners was established to oversee the construction of the State Hospital for the Insane.

Architect Stephen Vaughn Shipman was commissioned to design the facility based on the Kirkbride Plan.

[4] Shipman later designed a sister facility near Oshkosh and several other Kirkbride plan asylums in Iowa and Illinois.

The main building at the original Wisconsin State Hospital for the Insane opened in 1860 with its west wing added by 1862.

[5] Around 1904, a three-story 154 by 57 feet (47 by 17 m) addition was made to the facility adjoining and to the north of the original central structure.

This brought the facility to a "comfortable" capacity of around 600 with a daily average number of patients at 611 for the year ending June 30, 1908.

[8] In 1904, a Typhoid fever epidemic killed at least a dozen at Mendota, forced a quarantine of the facility and resulted in Superintendent Bullard's resignation in July 1904.

It was added to allow some patients more activity and outdoor time and supplying the facility with additional farm produce.

It resulted in around 30 dismissals of staff and officials from state mental health facilities in Mendota, Winnebago and Waupun.

[13] In the 1940s, a number of newspaper reports decried the facility as a "firetrap" with patients occupying attic areas of the building.

Kohler said at the dedication that it had been his goal to demolish the old Kirkbride plan buildings at Mendota and Winnebago hospitals.

In one of his last ceremonial functions as Governor he said that he "would never rest until these ancient, gray firetraps are completely demolished."

[18] The original structure was still around in 1960 for its centennial and was known as "Old Main", but the second and third floors of the wings were not being used for patients due to fire-related safety concerns.

[7] However, after replacement structures finished in the late 1950s and early 1960s, demolition began on the west wing of Old Main starting in September 1964.

[22][23][24] In 1974, MMHI received the American Psychiatric Association's Gold Achievement Award for the program,[25] also known as the "Madison model".

Governor Patrick Lucey (D) urged the Legislature to close Winnebago and Democrats in the State Assembly Finance committee supported that effort.

In 2007, state officials admitted that there was an inappropriate, intimate relationship between a female caregiver and male patient at MMHI.

[33] In November 2010, another female nursing assistant was charged with 2nd degree sexual assault of a male patient at MMHI.

[34] In July 2010, federal investigators said the Mendota Mental Health Institute failed to provide adequate treatment for its patients.

[38] In September 2010, MMHI announced they would not be accepting additional patients in the adult assessment treatment unit (AATU) after December 1, 2010.

The district includes the main two-story brick building and 17 "Tudor-inspired Craftsman style" cottages in a campus like setting.

Regaining control of Memorial Hospital from the Veterans Administration allowed the state to move patients out of the 90-year-old main building and out of upper floors while replacement facilities were constructed in the 1950s.

The Mendota State hospital had a cemetery for patients that died at the facility located about 1/2 mile north of the original complex.