The U.S. Sanitary Commission was organized by civilians June 1861 to assist the army, specifically to provide care for the sick and wounded soldiers, and to protect their depended families.Dr. Henry W. Bellows, pastor of All Souls Unitarian Church in New York City and president of the Sanitary Commission, said the organization would attempt to do those things to improve life for soldiers that the government felt unable to do. After developing an enormous operational structure that at times employed 500 agents, the commission became involved in aid that ranged from field ambulance, nursing, and hospital service to the care and protection of discharged soldiers (which included helping solve problems with pension claims and collecting more than $2.5 million in solders wages).

The mark of the organization's determined "inquiry, advice and supply" efforts could be seen everywhere, from the battlefields to the lodges established near railway stations to give soldiers temporary shelter. The commission supplied more than 1 million nights' lodgings during the war. It not only maintained convalescent camps offering soldiers' special diets and attention but also furnished paper and stamps, had letters written for the men, and telegraphed relatives of the very sick.

The commission's members ,among them some of the country's best-known doctors and most prominent business, government, and civic leaders, served without pay. Hired workers field inspectors, nurses, cooks, and teamsters received small salaries. With its central office in Washington D.C., the commission formed more than 7,000 aid societies and had main branches in 10 of the north's largest cities. From the branches, whatever soldiers needed medicine, clothing, food, personal items was transported to them, usually by Sanitary Commission wagons. All this was financed by donations and by sanitary fairs; those in New York and Philadelphia realized more than $1 million each. During the war the commission and its branches raised and spent more than $7 million and distributed donated supplies valued at $15 million.