How was the important contribution of the Spanish and Hispanic Americans to the Battle of Yorktown overlooked or completely enveloped in urban myths? This question is part of a more comprehensive topic as to why the roles of the Spanish and Hispanic Americans are ignored or obfuscated in our 21st century perception of the American Revolution. However, there are specific references that can be examined to understand how the particular incident of the silver and gold from Havana has been viewed.
In The First Salute, Barbara Tuchman writes that, "By popular subscription, the money for de Grasse is said to have been raised in less than 48 hours, with the help of Cuban ladies who contributed their diamonds." In weighing this version, Tuchman relied on the account of a Swedish lieutenant in de Grasses fleet, Karl Gustaf Tornquist, and concluded, "Less romantically, Tornquist states that Cuba issued a cash order for 700,000 piastres, which was delivered in cash in five hours." 
The Tornquist account relies on third party information concerning the incident of fund-raising, and Tornquist was not considered a diplomat or confidante within the circles of French and Spanish missions. Tornquist was not aware of the importance of Saavedras charter by King Carlos, and refers to Saavedra as "a Spanish director general of the customs who was sojourning at Cap [Santo Domingo], made no difficulties in giving a draft on a far great sum in Havana without guarantee."
A story of the diamonds donated by the women of Havana became a historical fixture that would now be considered an urban myth. Several accounts of the fundraising refer to the donation of diamonds. Charles Lee Lewis, formerly a professor at the US Naval Academy in Annapolis, writes in his book, "The public treasury [in Havana] was assisted by individuals, ladies even offering their diamonds. Five hours after the arrival of the frigate Aigrette, sent by de Grasse, the sum of 1,200,000 livres was delivered on board." Professor Lewis also misspells Saavedras name as Salavedra, and reports that he is the Director of Customs who had to be persuaded to assist de Grasse. Professor Lewis relies on the reports by Tornquist and Georges Lacour-Gayet, neither of which contains references to diamonds or jewels. But the rumors of ladies with diamonds have persisted, and reappear as late as 2004 in Robert Ketchums Victory at Yorktown. According to Mr. Ketchum, "[de Grasse] was unable to acquire sufficient funds locally and sent a frigate to Havana, where the commander of the port informed the principal inhabitants of the Americans need and succeeded in collecting some 2.5 million livres, chiefly from the women, who produced cash as well as their jewelry as collateral."
One French historian, Jean-Jacques Antier, wrote that the French American women of the French Cape and Port-au-Prince offered their jewels for la cause amricaine. The Admiral, he reports, while appreciating the gesture of the women but probably perceiving that there would not be a ready exchange market for jewels in the war ravaged colonial market, declined the offer.  This incident may have provided the impetus for the urban legend of a donation of diamonds by the women of Havana.
 Barbara W. Tuchman, The First Salute: a View of the American Revolution, (New York: Ballantine Books 1988), 239.
 Karl Gustaf Tornquist, The Naval Campaigns of Count De Grasse During the American Revolution 1781 1783 (Philadelphia: Swedish Colonial Society, 1942), 53.
 Charles L. Lewis, Admiral de Grasse and American Independence, 138.
 Jean Marie G. Lacour-Gayet Georges, La Marine Militaire de La France sous Le Regne de Louis XVI (Paris: Librarie speciale pour LHistoire de la France et de ses Anciennes Provinces, 1905).
 Richard M. Ketchum, Victory at Yorktown: The Campaign that won the Revolution (New York:Henry Holt and Company, 2004), 177.
 Jean-Jacques Antier, LAdmiral de Grasse (Paris: Plon, 1965), 204.