Helmuth von Moltke's alleged statement the U.S. Civil War was an affair in which two armed mobs chased each other around the country and from which no lessons could be learned underlines a grave misjudgment of this war in contemporary Germany. Today, however, the American Civil War is recognized as the first modern war. It produced a number of lessons across the strategic operational and tactical levels that shaped the face of war. But the German observers failed to draw significant conclusions at the time. A wide variety of reasons inhibited a thorough and unbiased analysis. This study aims to analyze the German observations and to arrive at the causes that led to the underestimation and disregard of the lessons from the Civil War. The thesis provides a sketch of the Civil War and the situation of contemporary Germany. It then examines the German observers and their evaluations. Thereafter, the author reflects selected essential lessons of the war against the contemporary German military evolution. In a final step the conclusions of these sections will merge into an analysis of the causes, which prevented the German army from arriving at the lessons of the U.S. Civil War.