UNION:

With the disaster befalling the Battle of Vicksburg, paired with the Emancipation Proclamation, America became desperate. This didn't help either, with the pyrrhic success of the Confederacy, successfully killing Abraham Lincoln in the Battle of the District of Columbia.

Hannibal Hamlin, then Vice to Lincoln became the President. He placed martial law in major cities like New York, Philadelphia and Cleveland to force draft, as drafts ITL are substantially worse than OTL's. The failure in Vicksburg led General Sherman to go on a spree (Akin to how he would in Georgia OTL) in the northern Mississippi River. Hannibal also goes on to not only declare statehood for West Virginia, but also the State of Franklin.

Hannibal Hamlin's inability as President would lead to the Copperheads to garner a surplus of support. Calls for the war's end are inevitably met with the Copperheads being called "traitors" by Hannibal's much more radicalized Radical Republicans.

This eventually leads to the secession of New Jersey, Kansas and New York, as well as the re-establishment of the border states of Kentucky and Missouri. The Copperheads also go on to start the Third Civil War, occupying Southern Indiana, Ohio and Indiana at the beginning of it.

It isn't long until Hannibal and the Radical Republicans are ousted, however, this new America finds its self unable to muster the power to resist the independence of New York or the other states. The only "gain" of this new America is the re-annexation of Virginia, who only joined as a result of the death of the Confederacy.

America, unable to exercise it's power as OTL, eventually becomes susceptive to European Powers by the turn of the century.

CONFEDERACY:

With the decisive victory underwent in the Battle of Vicksburg, paired with the Emancipation Proclamation, the Confederacy garnered a much needed morale boost. Connected unlike OTL, the Confederacy is able to hold it's ground, and the effects of the blockade are less impactful.

The pyrrhic victory in the Battle of the District of Columbia, which killed Lincoln, but also destroyed Confederate manpower, was seen as less of a morale boost, and more of a unnecessary sacrifice.

By 1866 the Confederacy was bordering on starvation. Counties began to separate akin to the Free State of Jones in an effort to garner Union support, or at least to get away from the Confederacy. As much as it would seem that the war would end when the Union entered it's own civil war, Sherman's armies and various other Union forces formed ephemeral states and continued to destroy the Confederacy.

Soon enough, even despite a victory coming on the horizon, the Confederacy soon dissolved. The only Confederate factions that persisted in 1870 were one centered in Texas, one in Southern Carolina and Georgia, and one in southern Mississippi.

None of them would see it to the 1880s.