So, you are saying that the US never prospered because of the “treason” it committed against England?
And thus the stupidity of such a line of argument is exposed.
Since you seem to have difficulty understanding this quote, I will carefully explain it to you, in very simple words.
The quotation is ironic. Successful treason ceases to be treason, as it establishes a new order, resistance to which is itself now treason.
The Founders did indeed, by any measure, commit treason against the British Crown.
However, since their treason was successful, it became heroic resistance to oppression instead. As Patrick Henry famously said, "If this be treason, make the most of it."
They did.
Confederates did indeed commit treason against the United States and its Constitution by armed rebellion, which certainly meets the constitutional definition of the crime. None were ever prosecuted for this crime, but that doesn't mean the crime was not committed.