The United States Sanitary Commission was authorized by the Secretary of War on June 9, 1861, and approved by President Lincoln on June 13th of that year. It was a committee of inquiry, advice and aid dealing with the health and general comfort of the Union troops. Many Sanitary Fairs were held to raise funds for the Commission, and eight of them issued stamps. These stamps were not valid for U.S. postage, they were prepared for, sold and used at the fair post offices.