The relief work which was carried on for more than four years consisted of caring for sick negroes who were within reach of the hospitals, furnishing food and sometimes clothing and shelter to destitute blacks and whites, and transporting refugees of both races back to their homes. Nearly a hundred hospitals and clinics were established, and half a million patients were treated. This work was greatly needed, especially for the old and the infirm, and it was well done. The transportation of refugees did not reach large proportions, and after 1866 it was entangled in politics. But the issue of supplies in huge quantities brought much needed relief though at the same time a certain amount of demoralization. The Bureau claimed little credit, and is usually given none, for keeping alive during the fall and winter of 1865-1866 thousands of destitute whites. Yet more than a third of the food issued was to whites, and without it many would have starved. Numerous Confederate soldiers on the way home after the surrender were fed by the Bureau, and in the destitute white districts a great deal of suffering was relieved and prevented by its operations. The negroes, dwelling for the most part in regions where labor was in demand, needed relief for a shorter time, but they were attracted in numbers to the towns by free food, and it was difficult to get them back to work. The political value of the free food issues was not generally recognized until later in 1866 and in 1867. During the first year of the Bureau an important duty of the agents was the supervision of negro labor and the fixing of wages. Both officials and planters generally demanded that contracts be written, approved, and filed in the office of the Bureau. They thought that the negroes would work better if they were thus bound by contracts. The agents usually required that the agreements between employer and laborer cover such points as the nature of the work, the hours, food and clothes, medical attendance, shelter, and wages. To make wages secure, the laborer was given a lien on the crop; to secure the planter from loss, unpaid wages might be forfeited if the laborer failed to keep his part of the contract. When it dawned upon the Bureau authorities that other systems of labor had been or might be developed in the South, they permitted arrangements for the various forms of cash and share renting. But it was everywhere forbidden to place the negroes under "overseers" or to subject them to "unwilling apprenticeship" and "compulsory working out of debts."