Until scientists invent time travel, the best way to explore the back alleys, businesses, and main streets of mid-19th century Manhattan might be via the New York Public Library’s website.

Thanks in part to a grant from the Knight Foundation, the NYPL is currently in the process of digitizing their extensive map collection. So far, the institution has only processed 33,000 maps, but by the time they're finished, a staggering 435,000 documents will have been uploaded online for the public’s perusing pleasure.

Many maps in the collection were drawn after New York City’s Great Fire of 1835 destroyed 17 blocks of Manhattan. Surviving insurers employed a cartographer to sketch a series of maps depicting wards and neighborhoods they couldn't scope out themselves. The artist's detailed renderings depict small businesses, streets, and buildings, revealing snapshots of a long-vanished city.

The NYPL might be the brains behind the project, but a volunteer task force comprised of more than 1000 members is responsible for manually inputting or double-checking map data that the institution's computers don’t recognize. Interested in lending the library a hand, or simply love looking at old maps? Find out more about the crowdsourced project on the NYPL's website. 

[h/t Crain's New York]