Map of what a place used to be
Problem
People are naturally curious about the history of buildings and businesses around them — what that restaurant was before, what used to stand on that corner — but there is no easy way to find out. The information exists only in fragmented local memories and old directories.
Opportunity
A crowdsourced map app where users submit location histories (with a review/approval flow), letting anyone type an address or browse a street view and see what each place used to be.
Market analysis
A direct match already exists (When It Was maps historical businesses onto an interactive timeline by address), and beyond competition the idea dies on the classic cold-start problem: coverage is the product, and crowdsourced local history must reach critical density city by city.
Market · Local-history enthusiasts, nostalgia browsers and genealogists; broad casual curiosity but shallow engagement, with weak monetization signals.
Pricing · No proven model in this category; comparable UGC history projects run free or as passion projects, with free public archives (Library of Congress directories, Sanborn maps, Chronicling America) as the alternative.
Pros
- + Strong curiosity hook; 'what was here before' content travels well on local social media.
- + Existing fragmented sources (city directories, Sanborn fire-insurance maps, newspaper archives) could seed data programmatically instead of from zero.
- + The proposed review/approval flow shows the right instinct about data quality.
Cons
- − When It Was already implements the same timeline-of-a-place concept.
- − Cold-start is brutal: an empty map is worse than no map, and density must be won town by town.
- − Moderating local-history submissions is a Wikipedia-scale trust problem with no revenue engine behind it.
Existing / similar tools
Source
r/SomebodyMakeThis (Reddit)
If built, the winning move is to invert the crowdsourcing: don’t launch an empty map and ask for submissions, but mine one city’s digitized city directories and Sanborn maps to launch with real coverage, then let corrections and memories accumulate as UGC on top of a seeded base. That mirrors how Wikipedia beat earlier encyclopedias — start with structure, invite editing. As a business this is a hobby with server costs; as a single-city project with library partnerships it could become beloved local infrastructure, which is a different and more achievable ambition than a consumer app.