There is no evidence, however, that Washington was able to learn Latin. He quotes Latin mottos from time to time, but none of his letters or later documents evidence a reading knowledge of the language.
I take great comfort in that -- that I too have failed at something that the great George Washington failed at! If one cannot share successes with the high and the mighty, perhaps it is something to share their failures????
Update: after some further digging, I went back to Morrison's book and found that I had mistakenly read the date of Washington's purchases. Washington didn't purchase the Latin books after the Revolution, he purchased them in 1760, before the French & Indian War! My apologies for not getting the timeline right.