"but your precious Confederacy held on to it long after Lincoln was dead and gone".
The Confederacy died at Appomattox Courthouse (and the principles of the American Revoloution along with it). You can say it lasted another month because some units hadn't formally surrendered yet if you want. But that hardly supports your remark.
You say the Confederacy died at Appomattox. But most Southerners would say it lived on, even to this day. The Confederate flag has been a rallying symbol for any number of Southern causes.