A contemplation of the compleat attainment (at a period earlier than could have been expected) of the object for which we contended against so formidable a power cannot but inspire us with astonishment and gratitude. The disadvantageous circumstances on our part, under which the war was undertaken, can never be forgotten. The singular interpositions of Providence in our feeble condition were such, as could scarcely escape the attention of the most unobserving; while the unparalleled perseverence of the Armies of the U States, through almost every possible suffering and discouragement for the space of eight long years, was little short of a standing miracle.
A good video from the Civil War Trust looking at the American Revolution, in many ways our First Civil War. I have spent over half a century looking at the Revolution and I agree with Washington that its outcome was very much a miracle, with the Patriots defeating not only the British but also the Loyalists. Washington and the men he led fought the most lop sided struggle in our history and prevailed against the odds.