This previously classified military analysis of the German Invasion of Poland was conducted by the United States War Department in 1941. Included are six maps that were part of the original analysis: terrain, communications and permanent fortifications (map 1); dispositions of opposing forces on August 31 and German Plan (map 2); situation at dark on September 5 (map 3); situation at dark on September 8 (map 4); situation at dark on September 14 (map 5); and situation at dark on September 20 (map 6). The German campaign plan is reviewed as well as what was known of the Polish plan at the time. There is also an analysis of comparative fighting strengths and a list of the principal commanders and their units. This is a rare book and a valuable reference for every student and scholar of military history.