The Bureau of Refugees, Freedmen, and Abandoned Lands, also known as the Freedmen’s Bureau, was established in the War Department by an act of Congress on March 3, 1865. The Bureau was responsible for the supervision and management of all matters relating to the refugees and freedmen and lands abandoned or seized during the Civil War. Bureau functions included issuing rations and clothing, operating hospitals and refugee camps, and supervising labor contracts between planters and freedpeople. Info courtesy of the National Archives.
Available here are the first twenty pages of the Freedmen's Bureau labor contract book created in Williamson County, TN between 1865 and 1866. This book records the contracts entered into by freedpeople after the end of the American Civil War.