In the 1850s the Grand Trunk Railway was built, connecting Sarnia to Montreal, through the area where Riverdale now sits. The railway brought industry and population growth to the rural area and the community of Riverside was born between Eastern Avenue and Queen Street. These railway tracks are now part of CN Rail after the Grand Trunk Railway ran into financial problems and was nationalized.
The un-incorporated community of Riverside joined the city of Toronto in 1884 becoming the second community, after Yorkville, to join the growing city. The neighbourhood was later renamed Riverdale after the park along the river.
At the time the only quality crossing over the Don River was at Queen Street. The connections across the river continued as the community grew. In 1888 the Don river was straightened and Gerrard street was extended over the river. In 1889 a streetcar line was opened on Broadview connecting the Danforth to downtown enabling more growth. In 1918 the Prince Edward Viaduct was opened, connecting Danforth Avenue to Bloor street allowing the area to the north of the Danforth to develop.