Special Field Order 15 was actually a series of Special Field Orders issued on 16 January, 1865, under a single numeric designation. These field orders set aside a huge swath of the Atlantic Coast in the South for the exclusive settlement of freed slaves, established an administrator for the redistribution of the land, and encouraged freed slaves to join the Union Army. Although Special Field Order 15 did not last long, as it was repealed in the fall by President Andrew Johnson after the assassination of Abraham Lincoln, many people consider it to be a landmark in American history, and it is often used as a precedent in court cases which involve reparations for the descendants of slaves.

These field orders were issued by General William Tecumseh Sherman after meeting with 20 prominent black religious leaders in Savannah, Georgia. Special Field Order 15 was a response to a very real problem, the issue of what to do with the untold numbers of freed slaves in the American South. Many of these people had joined Sherman's March to the Sea, and he was unable to care for them and unsure about what to do with them. Special Field Order 15 established a method for dealing with freed slaves while also punishing the South.

Under Special Field Order 15, the lands between Charleston and the Saint John's River in Florida were confiscated for 30 miles (48 kilometers) inland, and broken into 40 acre parcels. Black families were entitled to a parcel each. Subsequently General Sherman ordered the army to loan mules to the families to work the land, leading to the widespread use of the phrase “40 acres and a mule” in the American South. Naturally, this land was already owned and occupied, primarily by rice planters, but Sherman planned to expel them to make way for the resettlement.

Special Field Order 15 also specified that Brigadier-General Rufus Saxon would administrate the plan, dealing with the diverse issues involved, ranging from confiscating the land to creating new deeds for black landowners. This series of field orders was only one among many designed to deal with the cascading problems associated with Reconstruction, as Americans attempted to rebuild a country torn apart by Civil War.

Had Special Field Order 15 remained in effect, it certainly would have been a radical legacy. The thought of confiscating and redistributing land would sound suspiciously like Communism to most modern Americans, even in the context of reparations, and the character of that region of the United States would undoubtedly be markedly different. As it is, several people have attempted to sue the United States government for reparations related to slavery, arguing that Special Field Order 15 indicated a good faith belief in reparations on the part of the government.