 With the building of the first railway to Toronto from the west in 1855, Mimico, near Lake Ontario, petitioned the government for a post office to be called Mimico in 1858.In 1860, the original northern Mimico petitioned for its own post office, using the name Islington, which was suggested by the wife of Montgomery's Innkeeper who was born in Islington, England (now a part of London).A second railway was built at the bottom of the escarpment (just south of Dundas) preventing the collapse of Islington during the railway age.