From A Hog on Ice by Charles Earle Funk:

white elephant

That large portrait of your wealthy Aunt Jane, given by her and which you loathe but do not dare to take down from your wall; that large bookcase, too costly to discard, but which you hope will be more in keeping with your future home; these, and a thousand other like items are ''white elephants" - costly, but useless possessions. The allusion takes us to Siam. In that country it was the traditional custom for many centuries that a rare albino elephant was, upon capture, the property of the emperor - who even today bears the title, Lord of the White Elephant - and was thereafter sacred to him. He alone might ride or use such an animal, and none might be destroyed without his consent. Because of that latter royal prerogative, it is said that whenever it pleased his gracious majesty to bring about the ruin of a courier who had displeased him, he would present the poor fellow with an elephant from his stables. The cost of feeding and caring for the huge animal that he might not use nor destroy - a veritable white elephant - gave the term its present meaning.

Incidentally, as a matter of English history, Charles I of England had the sad experience of receiving such a gift, a figurative, if not literal, white elephant. In 1629, just at the time that the king, faced with a recalcitrant Parliament, was desperately trying to raise funds by any measures, even to the extent of bartering the crown jewels, the Emperor of Siam sent him an elephant and five camels. Though the account does not say that the elephant was white, the cost of keeping the beast, estimated at £ 275 a year, was so great that the queen was obliged to put off her "visit to 'the Bath' to a more convenient season, for want of money to bear her charges," for, as the record goes on to say, aside from that cost for feed and care, "his keepers afirme that from the month of September until April he must drink, not water, but wyne, and from April unto September he must have a gallon of wyne the daye."

to eat crow

To abase oneself; be obliged to accept or do something extremely disagreeable.

Though this homely American saying is not found in print prior to 1877, there is no doubt that it was in common use many years earlier. According to an account in an 1888 issue of the Atlanta Constitution, the incident which gave rise to the expression occurred along the Niagara River toward the end of the War of 1812. During an armistice it was the practice of the opposing garrisons to go hunting. While on such an expedition a hapless New Englander crossed the river in search of larger game, but finding nothing took a shot at a passing crow and brought it down. A British officer, hearing the shot, resolved to punish the intruder and came upon him just as the Yank was reloading his gun. But as the officer was unarmed he used diplomacy; he complimented the soldier upon so fine a shot and asked to see so excellent a weapon. The unsuspecting soldier passed it over, whereupon the Britisher brought it to his shoulder, covered the Yank, and berated him for trespassing; then, to humble him thoroughly, ordered him to take a bite out of the crow. Despite all pleas, the soldier was forced to obey; then, after a warning never to cross the river again, the officer handed back the soldier's gun and bade him be gone. But when the Englishman turned to go back to his camp, the quick-witted New Englander, now having the weapon, stopped him and ordered him to finish eating the crow. The officer begged and implored, but the soldier was firm; promises of money and gold were sternly refused; the Britisher, faced with death, ate the crow.

The incident became known, the story says, because the British officer went next day to the American commander and demanded that the soldier be punished for violating an armistice, telling his own version of the affair. When the soldier was brought in, the American captain asked him if he had ever seen the Englishman before. After several attempts to speak, the stuttering Yankee finally had the wits to say, "W-w-why y-y-yes, Captin', I d-d-dined with him y-y-yesterday."