We Europeans tend to think that the US have no history. Incidentally, this happens to be true from an European viewpoint, as their written records are quite recent (a different perspective would give a more complex vision). Recent history shows some curious features. The Genealogical Map of Pennsylvania, compiled in 1933 by the State Government and already in its tenth edition in 1985, shows the complex journey of the subdivision of the state during the XIXth century, and even the XVIIIth century purchases. New York and Pennsylvania where part of the same country, but even so Erie county was ceded by NY to PA to ensure an access to the great lakes…. The map is useful not by locating the main family names, but the administrative divisions that allow you to go to the proper county office. In most of Europe the reference would be the parishes, as they were long the ones having the baptism registration books…