Medical officers who, like myself, served overseas in World War ll, and who observed the management of casualties with and without the use of whole blood, are peculiarly qualified to appreciate the achievements of the whole- blood program. Its results unfolded before our eyes. In forward hospitals, we saw men saved from death and sometimes, almost brought back from the dead. In fixed hospitals, we received wounded men who once would have died in forward hospitals, or even on the battlefield. We received casualties with the most serious wounds in good condition. With the aid of more blood, we performed radical surgery upon them, and we watched them withstand operation and, with still more blood, recover promptly from it. There are more than the usual reasons for the preparation and publication of this volume on the whole-blood program. A major reason, of course, is the impact this therapeutic advance has had upon medical care, civilian as well as military. Another reason is to keep faith with the multiple personnel who planned and operated the whole-blood program, and with the millions of American citizens whose gifts of their own blood saved the lives of so many American soldiers, who otherwise would have died.