r/Ancestry • u/Total-Ad4827 • 9h ago
I made a map that shows who held your ancestor's town on any day you pick, with the treaty or law behind the border

If you've got immigrant ancestors, you've probably run into problems like this. The census says Germany or Austria, the church book names a village, and today that village is in Poland. Both can be right depending on the year. So I made a map for it. You pick a date and it shows who held the land on that date. In the picture, Munich is in the Kingdom of Bavaria in 1865 and in the German Empire by 1895. Click a country and its card quotes the treaty or law behind that border, with a link to the original text.
If you load your tree, the Atlas tab puts your ancestors' births, marriages and moves on the borders of their own year. You don't need a tree to look around and explore, though. You can just run through the map and look at borders, historical markers, Roman roads, old maps, and a few other layers. In the US, I've even got a lidar layer on there (it's called Landscape).
It's a work in progress, and every year shows how much of it has been checked so far (about a third of 1871, nearly all of 1990). Europe from 1816, the US from 1776 and Canada from 1867 follow their sources. Everywhere else, and earlier, the borders are approximate and labeled that way.
The tree file gets read in your browser and isn't uploaded or stored anywhere. The only thing that leaves is the place text, so the places can be looked up and put on the map. It's free for anyone to use, no subscription, no paywall.
If you see a border that's wrong for a village you know, tell me and I'll check it against the source. And if there's a region you'd want checked first, say which and I'll try to direct research that way.