I run https://pastmaps.com as a lil' solo bootstrapped labor of love. Think Google Maps, but for OLD maps. It has 185K+ fully georeferenced high-res maps covering all of America, as well as satellite, LiDAR, and 3D layers to enable exploration through space and time. History is cool yo. And apparently lucrative - it currently makes ~$5000/mo and is slowly but surely growing through word of mouth