The double defeat of 1870/71 and its political consequences were a severe shock for the outgoing superpower France. France recovered rather quickly materially, but not so morally. There were manifold reasons for the unprecedented military disaster of the “Grande Nation”, when not only the army of the empire declined nearly completely, but finally also a big part of the newly established republican armed forces. Often immature, several corps of the imperial army had to go to battle at the border, while thousands of reservists were waiting for their forwarding on the train stations in the hinterland. In the course of the first operations already the overwhelming numerical superiority of the Prussian-German army of conscripts facing the French army of regulars had proved to be a decisive disadvantage, even more than the excessive conceitedness of the political and military leaders of France, which led to serious organizational weaknesses in the course of the military build-up. At the beginning of the First World War all railways were used to their limits because of extensive measures of evacuation, as great parts of the population in the north of the country joined the retreat of the army. After the first still orderly evacuation transports, from 22nd August onwards panic mood began to spread among the population. Without official authorization, refugees from the regions threatened by the Germans occupied food supply trains coming back empty, and even did not hesitate to enter trains bringing back casualties. At the end of August 100,000 civilians beleaguered Lyon Station, desperately hoping for an opportunity to be transported south. Within ten days nearly 1.5 millions of people from the northern and eastern regions of the country poured on trains into the capital, from where they had to be brought further south quickly in view of the impending siege. The real miracle of Marne was the fact that, despite these aggravating circumstances, it was possible to reinforce the left French flank with a total of 533 troops trains in time. Until the 10th September, one day after the German withdrawal, the French supreme command, by means of the railways, had succeeded in moving a total of 20 infantry and 3 cavalry divisions - a quarter of the whole army, after all - from the right to the left military flank. Together with the then arriving formations from the rest of the country and the newly reinforced British expedition corps, the Allies suddenly had 41 divisions at their disposal on the left flank, facing only 24.5 German divisions. Thus, a temporary stop of the German advance on the right flank seemed unavoidable. Thus, in the First World War France was spared a military disaster like 1870, and the railways contributed their considerable share. The long-time objective, however, to spare the country another enemy occupation, could finally not be obtained with their help. Even a partially excellent network of railways could not be a substitute for correct strategic decisions.