A group of African Americans sent the Petition of Black Residents of Nashville to the Union Convention of 1865 asking for an immediate end to slavery in Tennessee. Why do you think those that signed the petition placed so much emphasis on their loyalty to the Union cause during the Civil War?

As the Civil War neared its end in early 1865, a group of black residents of Nashville, Tennessee, petitioned the United States government to end slavery. They counted on the federal government's antipathy towards the Confederacy to further their cause.
The writers of the petition believed that Southern slave owners would try to reclaim their slaves at the end of the war and would try to force them back onto plantations. The writers of this petition furthered their cause by connecting slavery with the corruption and disloyalty of the Confederacy and wrote that the same corruption that had caused the Confederate states to break away from the Union had forged the Confederacy's close connection to slavery. In other words, both the Confederate government and its system of slavery arose from corrupt, evil roots. By making this connection, the writers hoped to win over the federal (Union) government, which opposed the Confederacy and was about to win the war against them.
The writers of the petition differentiated themselves from the Southerners who were faithful to the Confederacy and stated that they were loyal to the Union to further convince the federal government to grant their freedom. They stated that if granted their freedom, they would dedicate themselves to defending the Union. They used concepts from the founding of the nation, including the idea of "natural rights," to argue that it was also their natural right to enjoy freedom after the war. Their established allegiance to the Union would strengthen the federal government in the former Confederate states after the war was over.
http://www.freedmen.umd.edu/tenncon.htm