https://www.historicaerials.com/viewer https://www.historicaerials.com/viewer is amazing for this purpose. They've aggregated decades of aerials and topo maps c

https://www.historicaerials.com/viewer https://www.historicaerials.com/viewer is amazing for this purpose. They've aggregated decades of aerials and topo maps covering most of the US. A great way to analyze urban development patterns and answer local historical questions.