What’s in a date?

Many maps mention a date. This date does not necessarily refer to the actual date of the relevant map. They refer to the first year of issuance of the map, possible in an earlier version of the atlas. Many maps were published during several years without any changes made. The dates we list are usually accurate to within 10 years for older maps (pre 1700). We make best efforts to use our available reference tools to accurately date each map we offer for sale.