In 1830, Thomas and Margaret Montgomery leased 200 acres of Clergy Reserve land between Islington Avenue and Royal York Road, running south from Dundas to Bloor Street. They built a large Inn of stone from the Mimico Creek valley, adding exterior stucco and two wings in 1838. In the 1840s, they expanded their property to 400 acres. The Inn operated until about 1856, but the family continued to farm their large property using hired farm superintendents. The portion of the property around the Inn remained in the family, operated by tenant farmers, until 1946 when it was sold to a Presbyterian church. In 1960, it was purchased by developer, Louis Mayzel, who planned to replace it with a strip mall. The Etobicoke Historical Society convinced Mayzell to save the Inn and sell them the property in 1962. It was purchased two years later by the Township of Etobicoke, which restored the Inn and opened it as a museum in 1975. Montgomery's Inn is the oldest building in Islington, and the third oldest in all of Etobicoke.