The Netherlands American Cemetery and Memorial is the only American military cemetery in the Netherlands. The cemetery site has a rich historical background, lying near the famous Cologne-Boulogne highway built by the Romans and used by Caesar during his campaign in that area. The highway was also used by Charlemagne, Charles V, Napoleon, and Kaiser Wilhelm II. In May 1940 Hitler's legions advanced over the route of the old Roman highway, overwhelming the Low Countries. In September 1944, German troops once more used the highway for their withdrawal from the countries occupied for four years.