The following is from Snopes and explains the origin of this supposed "vision":
"Washington's Vision" is a narrative presented as the 1859 reminiscences of 99-year-old Anthony Sherman, who was supposedly present with George Washington's army at Valley Forge during the winter of 1777 and overheard Washington tell an officer that an angel had revealed a prophetic vision of America to him. The passage of more than 150 years has since obscured the origins and purpose of this narrative, leading many who encounter it now to believe that it is a true account of an incident from Washington's life rather than a fictional tale created for political purposes long after Washington's death.
The tale of "Washington's Vision" was penned by Charles Wesley Alexander (1836-1927), a Philadelphia journalist who published The Soldier's Casket, a periodical for Union veterans of the Civil War. Writing under the pseudonym "Wesley Bradshaw," Alexander authored several fictional "vision" or "dream" pieces featuring historic American figures which were published as broadsheets and in various newspapers during the Civil War and were later offered for sale through advertisements in the pages of The Soldier's Casket, with the artificial separation between the real Charles Alexander and the pseudonymous "Wesley Bradshaw" allowing the former to unashamedly laud the latter's works.
The meaning of "Washington's Vision" was apparent to Alexander's contemporary audience. First published in April 1861 (at the outbreak of the Civil War) and full of references to "Union" and "Republic," this account of Washington's praying "to God in secret for aid and comfort" during the darkest days of the American Revolution and being visited by an angel who revealed to him a vision of the United States victorious was an obvious allegory for Unionists whose America was facing its greatest crisis since the revolution: a civil war pitting one half the country against the other in a struggle that threatened the existence of the Republic.
During the war Alexander penned several similar tracts featuring both historical and contemporary American figures (e.g., Abraham Lincoln, Jefferson Davis, Ulysses S. Grant), including "General McClellan's Dream," a narrative in which the general-in-chief of the Union Army fell asleep at his desk and was awakened by a vision of George Washington, who admonished the general for sleeping at his post and revealed to him secret rebel plans which he urged McClellan to act on quickly in order to prevent Washington, D.C. from falling into Confederate hands. Alexander also published even more fantastical tales, including several about female Union soldiers with supernatural powers and one of a demonic Englishwoman who fought on the side of the Confederacy.
As the Journal of the American Society for Psychical Research noted of "Washington's Vision" and "General McClellan's Dream" in 1917:
"It seemed to us that the remarks which prefaced the dream itself plainly intimated that the latter was a literary production written for a patriotic purpose.
The [article] is from the pen of Wesley Bradshaw, Esq., and makes a fitting companion to "Washington's Vision," which sketch, written by the same author, at the commencement of our national difficulties, was widely copied by the press, and commended by Hon. Edward Everett as "teaching a highly important lesson to every true lover of his country." There is here no attempt to put forth the "dream" as authentic. It is a "sketch" written by a gentleman who shortly before had written another sketch about a dream or vision attributed to Washington."
(Although an officer named Anthony Sherman did serve in the Continental Army, he was at Saratoga under the command of Benedict Arnold at the end of 1777 and therefore wasn't with Washington's forces at Valley Forge during the winter of 1777-78, so it's likely mere coincidence that Alexander chose that appellation for the name of his fictitious narrator.)
Alexander's expression of the theme that America can never be conquered by external enemies but can be brought down only through the failings of its own citizens gained renewed currency in 2001 among Americans in need of booster shots of patriotism after the events of September 11, and it is reminiscent of thoughts delivered for real by a revered American historical figure: Abraham Lincoln's address before the Young Men's Lyceum of Springfield, Illinois, on 27 January 1838:
"At what point shall we expect the approach of danger? By what means shall we fortify against it? — Shall we expect some transatlantic military giant to step the Ocean and crush us at a blow? Never! — All the armies of Europe, Asia and Africa combined, with all the treasure of the earth (our own excepted) in their military chest; with a Buonaparte for a commander, could not by force, take a drink from the Ohio, or make a track on the Blue Ridge, in a trial of a thousand years. At what point then is the approach of danger to be expected? I answer, if it ever reach us, it must spring up amongst us. It cannot come from abroad. If destruction be our lot, we must ourselves be its author and finisher. As a nation of freemen, we must live through all time, or die by suicide. "
Here is a fellow who compares it to the Mosiah Hancock statement (which I heartily endorse):
He has said that the vision of George Washington might be a fake. That very well could be. It could also be that it did happen in some way and that simply be that Satan is attacking it just as he has attempted to discredit visions by Joseph Smith. I only offer this based on what Joseph Smith as recorded by Mosiah Hancock in Mosiah Hancock Autobiography, p. 28, BYU Special Collections. If you look at the two accounts they speak of the same event in similar ways
Washington: "... he sprinkled it upon Europe, Asia, and Africa." "Then my eyes beheld a fearful scene. From each of these continents arose thick black clouds that were soon joined into one. And through this mass there gleamed a dark red light by which I saw hordes of armed men. These men, moving with the cloud, marched by land and sailed by sea to America, which country was enveloped in the volume of the cloud.
Joseph Smith: ""The United States will spend her strength and means warring in foreign lands until other nations will say, “Let’s divide up the lands of the United States”,
Washington: "And I dimly saw these vast armies devastate the whole country and burn the villages, towns and cities which I had seen springing up." "As my ears listened to the thundering of the cannon, clashing of swords, and the shouts and cries of millions in mortal combat..."
Joseph Smith: "then the people of the U.S. will unite and swear by the blood of their fore-fathers, that the land shall not be divided. Then the country will go to war,"
Washington: "Instantly a light as of a thousand suns shone down from above me, and pierced and broke into fragments the dark cloud which enveloped America. At the same moment the angel upon whose head still shown the word 'Union' and who bore our national flag in one hand and a sword in the other, descended from the heavens attended by legions of white spirits. These immediately joined the inhabitants of America, who I perceived were well-nigh overcome, but who immediately taking courage again, closed up their broken ranks and renewed the battle." "Again, amid the fearful noise of the conflict I heard the mysterious voice saying, 'Son of the Republic, look and learn.' As the voice ceased, the shadowy angel for the last time dipped water from the ocean and sprinkled it upon America. Instantly the dark cloud rolled back, together with the armies it had brought, leaving the inhabitants of the land victorious."
Joseph Smith: "and they will fight until one half of the U.S. Army will give up, and the rest will continue to struggle. They will keep on until they are very ragged and discouraged, and almost ready to give up-when the boys from the mountains will rush forth in time to save the American Army from defeat and ruin. And they will say, ‘Brethren, we are glad you have come, give us men, henceforth, who can talk with God’. Then you will have friends, but you will save the country when it’s liberty hangs by a hair, as it were.”
White spirits coming down from the heavens associated with priesthood holders coming down from the mountains who can talk with God and through the priesthood power perform miracles that cause the enemy to be defeated?
2 Corinthians 13:1: "...In the mouth of two or three witnesses shall every word be established."??
And so, yes...... just as you can attempt to attack Joseph Smith's visions and experiences with dubious sources; NO, I do NOT buy the garbage that circulates from godless (liberal) people. I have personal revelation combined with a little reasoning/logic that trumps anything out there. Case closed....