If you're a prototype modeler, you probably enjoy finding where old photographs of your railroad were taken. If you're lucky and the trees haven't encroached too much, you may even be able to replicate the scene. If you're really good, you can then morph between the two photos and see the old view morph into the new view and vice-versa (click here to see how Bill Schneider did this to great effect).
Well, today I discovered a way to do that with maps. We prototype modelers rely heavily on maps to show us where our ROW went, what tracks were there, the buildings, etc. But depending on what era you model, things could have - and probably did - change dramatically over the years. If you want to see how, run - do not walk - over to the USGS's Historical Topographic Map Explorer. There you can enter the location you're interested in, click on the map of the location when it pops up, and the software will give you a timeline across the bottom with links to all the maps available for that location, plotted on the timeline by date and scale.
I'm familiar with parachuting into old maps online, but now that I've started playing with this new tool, it's really fun to toggle back and forth between today and "the past." Bonus: the older your prototype and the earlier it was abandoned, the more fun it is.
So go check it out - but if after seeing the old maps you discover you did something wrong with your trackwork or building placement, don't blame me!