(With many thanks to Georgepatton, who inspired the original idea and wrote this lovely desription.)
The Unorganized African Territory of the United States
After the end of the Civil War (1861-1867), the United States was confronted by two intractable problems, which it seemed impossible to solve simultaneously. First was the problem that confronts all states in the aftermath of domestic bloodletting: the defeated. The great masses of ex-Confederate soldiers and supporters, disenfranchised and dispossessed by an embittered North, swarmed disconsolately across the ruined South, and there were many yet still willing to fight and die on their feet, rather than strangling in the mud an inch at a time.
Second, of course, were those who the Confederates had fought to hold in chains: the negro. Freed from his chains, and armed with the ballot, the rifle, and the strong right arm of the Federal Marshal, prosperity might at last be within his grasp. But, of course, it was not to be, for hearts are not so easily won as wars.
Terrorism, cycles of killings and revenge killings, race riots, bread riots, labor riots, just plain old riot riots: there was no end to it. The Hamlin and Davis administrations grappled fruitlessly with the problems, and as the body count mounted, the public began to ask when, exactly, peace was scheduled to arrive.
The answer would come from a much unexpected source: Abraham Lincoln, who had retired from politics to repair his shattered health and family after the War, returned to answer the national cry for peace once more. He looked across the Atlantic Ocean, to the continent from which all this sorrow had sprung: Africa.
Lincoln, who had once thought that the races might live in harmony in the United States, sorrowfully returned to his belief that separation was the only true path to peace. But that was not all bad, he reasoned, for the American negro, by his residence upon that continent, had indelibly acquired respect for the great virtues of the land: freedom, liberty, democracy, education, and hard work. And the African negro languished in poverty, ignorance, slavery. The great civilizing mission of the United States could be brought back to Africa, bringing peace and prosperity to two lands in the same solution.
But the great masses of American negroes had no great skill at arms or settler organization. Some class of men with those skills would have to lead them. Who better, suggested General Sheridan, than that other people without a future in America: the Confederate veteran?
And so it was that black and white at last found unity of purpose, in the Great Grey Fleet, which hurled itself upon the African coast in 1879. By dint of blood and iron, they forged a great country upon that continent, bringing the flag of the United States to the darkest corners of Africa. Even the European trading posts fell before the advancing tide of liberty, with covering fire from Lincoln and his Great Civilizing Christian Mission program that so many in the Old World were willing to accept.
The natives, sadly, were ignorant and superstitious, and it was great and difficult work to bring them into the light of knowledge and progress. The savage proto-caliphates of the Musselmen statelets in the interior were especially resistant, and it was only the military genius of Pete Longstreet, and the selfless devotion of thousands of his negro troops, that set the cross above the crescent.
But, eventually, for all the tales of blood and thunder, of the noble Christian missionary, of the valorous negro soldier giving his life for his white comrade (and even for all the excoriation Sam Clements could muster in The Darkest River), the popular imagination would turn elsewhere. The American West, and beyond it the Pacific beckoned, and the Europeans were forever preoccupied by slaughtering one another at the behest of callous princes.
These days, the generals in the UATUS (or rather their public relations officers) will tell you they're waiting on Congress to provide some legislation to organize the territories, appoint territorial governors, and move the process of statehood forward, and that the 'current geopolitical situation being what it is', they can't speculate on when that will be.
They're good boys, though, these Benjamin Junior and Longstreets the Third and Sheridans the Fourth: the praise the Constitution to high heaven, take assiduous action to protect the rights of each and every person in the UATUS, regardless of race, tribe, color, or National Labor Service status, and they even go so far as to collect federal mineral excise taxes, depositing them in numbered Swiss bank accounts for the day when the Treasury can collect. And there's a lot of mineral taxes to collect.
Legally, of course, trade in UATUS-sourced diamonds and gold and oil is not supposed to take place. The UN isn't clear about the status of resources extracted from apparently military-occupied territory, but luckily, that's not a problem, since that cargo ship that left Monrovia two weeks ago is definitely not the same one that put into port at Boston yesterday, and those Diamond Trade Board Certificates are perfectly in order, sir (please be careful with them or the ink will smudge).
The generals acknowledge, of course, the on-going problems of the territories: the endemic brushfire conflicts on the edges of the districts, the slow progress of education and infrastructure, the difficulties faced by the Agriculture Board in improving beyond subsistence farming in many places, and, of course, the on-going necessity for martial law outside a few coastal cities. Still, once Congress gets its act together and pushes through that important legislation, they say, it'll be smooth sailing from there on out!