Who coined "United States of America"?

This letter from Washington to Reed mentioned by Moylan oozes with subtlety and sarcasm. For the calculating Washington, it suggests the veiled language of a man telling his most trusted and perceptive aide that all-out war is coming and, perhaps, that it could only lead to a declaration of independence, which happened seven months later.

“We are at length favoured with a sight of his Majesty’s most gracious speech. Breathing sentiments of tenderness and compassion for his deluded American subjects; the echo has not yet come to hand, but we know what it must be….”

In Moylan’s Jan. 2 letter, maybe “United States of America” was a slip of the pen, so to speak – the idea of a new nation that, until then, could only be whispered. Nevertheless, it is concrete evidence that the phrase “United States of America” was written, and most likely spoken, in a home in Cambridge converted to a war office at the dawning of America’s revolutionary year. Whether Washington, Moylan, or even Reed should be credited is somewhat beside the point. In many matters, all three spoke with one voice – the voice of the commander-in-chief of what would become the United States of America.