As soon as the A. E. F. began reaching France in force and its command realized that American troops were to bear their full share of the future fighting, the importance of identifying the slain and their graves asserted itself as a major problem. The experiences of the other armies had not been pleasant in this respect, and the command of the expedition did not underestimate the difficulties. The British Army, for instance, had lost the identification of fully 40 per cent of its dead. This was not due to the lack of identification of the dead at the time of burial so much as it was to the obliteration of cemeteries by shell fire as the battle front surged back and forth over many kilometers of ground. After the American Army reached the front in force in the summer of 1918, it never knew a major retreating action; its movement was always forward, and its cemeteries, always in the rear, were never destroyed. The result was that the A. E. F. maintained an extraordinarily high percentage of identification. Less than 2 per cent of its graves, after all the evidence was in, housed unknown dead. The first step taken by the A. E. F. to accomplish this result was to establish, in the summer of 1917, a Graves Registration Service in the Quartermaster Department. The original plan was for this Service to send out field units to take complete charge of the disposition of remains--burying the dead on the battle fields and elsewhere, acquiring land for cemeteries, keeping the records of burials, and maintaining the cemeteries in the future. Sentiment among the troops themselves brought about a change in this arrangement. As soon as the divisions suffered their first casualties, the comrades of the dead men could not bear to have their friends buried by strangers, even though the strangers were Americans in the American uniform. Consequently G. H. Q. modified the original order, saying that “the dead must necessarily be buried by the units themselves. These units perform this duty as tribute to their dead.” Thereafter the Graves Registration Service merely recorded all burials and grave locations and looked after the graves. Such a system was maintained until the early autumn of 1918. Then the fighting reached its most intense stage, and our advancing forces could spare neither time nor energy for the proper burial of the slain. At this juncture the field units of the Graves Registration Service stepped in voluntarily, without waiting for special orders, and assisted in searching the ground for dead men and in burying them, enlisting such aid in the work as they could find on the spot. This was the time of the heaviest American casualties, and the units of the Graves Registration Service buried in all some 10,000 dead American soldiers.