What I mean by that is pretty much no one considered the CSA as being formally separate from the USA. Even to the federal government, the Uncle Sam didn't even formally renounce and kick out those who declared succession. And he was generous enough to not press charges of treason as many would have done.
You use the general term "Uncle Sam", and I can understand why. It's not as easy when you need to identify the human players. Who is 'uncle sam' in your statement?
Is it Lincoln? But he was killed quite early on. Is it the Vice President, now President Johnson? But his views of reconstruction were opposed by many.
Is it Thaddeus Stevens and Charles Sumner who were appointed by Congress to undo any work that President Johnson did toward Reconstruction?
Here are some brief quotes of Thaddeus Stevens view of reconstruction made in his "Conquered Provinces" article. Taken from (Documentary History Of Reconstruction, Walter L. Fleming,McGraw-Hill Book Company,1966)
"Congress alone can do it...Congress must create States and declare when they are entitled to be represented." p.(148)
"It is obvious from all this that the first duty of congress is to pass a law declaring the condition of these outside or defunct States, and providing proper civil governments for them. " p.(148)
"They ought never to be recognized as capable of acting in the Union, or of being counted as valid States, until the Constitution shall have been so amended as to make it what its framers intended; and so as to secure perpetual ascendency to the party of the Union; and so as to render our republican Government firm and stable forever." (p. 148)
From same source as above: Here is Charles Sumner's view of reconstruction also known as the "State Suicide Theory". In it he gives 9 resolves. This is a quote from the first.
"Resolved, That any vote of secession or other act by which any State may undertake to put an end to the supremacy of the Constitution within it's territory is inoperative and void against the Constitution, and when sustained by force it becomes a practical abdication by the State of all rights under the Constitution, while the treason which it involves still further works an instant forfeiture of all those functions and powers essential to the continued existance of the State as a body politic, so that from that time forward the territory falls under the exclusive jursdiction of Congress as other territory, and the state being according to the language of the law, felo-de-se, ceases to exist." p.(144)
Good-Ole-Rebel