GoKawiilNew tool 'mapsnap' automatically georeferences historic Sanborn insurance maps
A developer built mapsnap, a program that automatically aligns old Sanborn Insurance Maps—detailed block-by-block city surveys made from roughly 1870 to 1960—with modern geographic coordinates. The tool processes the maps' rich detail, including building materials, addresses, business labels, and heights, to make them usable in mapping software. The post explains the technical approach and why automating this process matters for historians and archivists.