Upon the debarkation camps at the Atlantic ports fell the chief work of splitting up the returning expedition into demobilization units. There were five major debarkation camps--Merritt, Mills, and Upton at New York, and Stuart and Hill at Newport News--besides numerous smaller centers at both ports. At the height of the return movement these camps were insufficient to accommodate the incoming thousands, and the Transportation Service used former training camps as debarkation camps, in both the Hoboken and Chesapeake districts. As long as Boston and Charleston acted as ports of debarkation they, too, made use of neighboring training camps. Of all of the debarkation camps, Camp Merritt was the largest. In it were to be observed some of the most interesting processes of troop demobilization. It was the principal camp both for reception of overseas casual companies and for the breaking-up of organized units and the formation of casual detachments for distribution among the thirty-three demobilization centers. During demobilization Camp Merritt was like a great terminal post office. The mail consisted of bulk consignments of soldier members of the disintegrating American Expeditionary Forces. It was the task of the post office to sort the mail for thirty-three principal destinations. The individual soldiers were thrown into receptacles called Hoboken Casual Companies, each, when filled up, consisting of two officers and 150 men, and each addressed to one or another of the demobilization centers. Each bore an identifying number, and the numbers ran consecutively, reaching well into four figures before the work came to an end. Special trains frequently left the two railroad stations which served Camp Merritt. Sometimes an entire train would be loaded with casual companies bound for the same center. Other trains were made up of special cars destined for different terminals. In the camp new casual companies in skeletal form were constantly being organized. Those scheduled to travel to the less populous sections of the country might be several days in filling up to standard strength. Others reached full size in a few hours. As soon as a casual company was complete, it was dispatched immediately to its proper demobilization camp. For several months in the spring and summer of 1919 the average interval between the time a skeleton company was formed and the time it was dispatched from camp was less than twenty-four hours.