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Travel back in time with a bird's-eye view of Toronto through the years

A new, free online map of Toronto lets users search for a location and then scroll through history to see a bird’s-eye view of how the city has changed over time.

The Toronto Historic Maps tool was built when local historical maps enthusiast Nathan Ng teamed up with Chris Olsen, a tech support employee at Esri, a California company that makes mapping software.

Ng had compiled a group of historical maps from the Toronto Library and Toronto archives and posted them in easy-to-browse format on his website. He blogged about how he would like to see someone make “a jazzed-up, interactive version, or a gigantic ‘all in one file’ image carefully stitched together.”

That someone was Olsen, who had recently created just that — using his skills and some of his company’s resources — for Cleveland and Pittsburgh.

The online mapping tool he made combines maps of Toronto ranging from 1818 to 1924 as well as aerial images from 1924 and 2012. Using a search field, you can locate addresses and landmarks and then scroll through to see the maps change over time.

Ng is happy with the result.

“To look at a given neighbourhood or street and slide through the years, and see how the buildings have changed over time — and sometimes, what’s also interesting is to see what’s stayed the same,” he said.

Olsen built the map viewer by “geo-referencing” the maps — entering control points on the maps into software that stitched maps of the same years together — and then lined them up year-over-year, adding a scroll bar that fades one map year into another, so the map evolves on a timeline.

“You can see how things change over time. You can see how a field becomes a network of streets and then there’s houses overlaid on it,” he said.

For example, if you search the St. Lawrence Market you can see the creation of the first brick market buildings, and see the waterfront get farther and farther away as generations of Torontonians built out into the lake.

Olsen said there are many more maps that can be added — for example, there are plenty of aerial images that he’s hoping to access and add to the map viewer.

Olsen’s mapping projects in other cities have been used by city planners, students and residents who are curious to learn about the history of their neighbourhoods.

“It gives you a sense of place and your own community,” he said.

To view the online mapping tool, go to

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