Final answer:
The Emancipation Proclamation is the document that declared the freedom of slaves in the Confederacy and authorized the enlistment of African Americans in the Union army and navy.
Step-by-step explanation:
The document that declared all slaves should be set free in the Confederacy and also allowed blacks to serve in the Union army and navy is known as the Emancipation Proclamation. Issued by President Abraham Lincoln on January 1, 1863, during the American Civil War, it proclaimed the freedom of slaves in the ten states that were still in rebellion, thus changing the character of the war. Following the Proclamation, the United States Army established the Bureau of Colored Troops with General Orders No. 143, embracing the inclusion of African American soldiers, who would become instrumental to the Union's victory.