It’s the ultimate spring-cleaning find: the great, great, great, great grandson of William H. Crawford, the U.S. Ambassador to France between 1813 and 1815 and later U.S. Secretary of War and Secretary of the Treasury was digging through a box of family heirlooms when he happened upon a trove of letters and documents received by his ancestor. Among the papers found in Mississippi were notes on the peace negotiations that ended the war of 1812, a hand-written opinoin by chief justice John Marshall, and documents from Crawfords time at the Treasury. But most impressive were two four-page letters from Thomas Jefferson.

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The earlier letter, written on Valentine's Day 1815, is no run of the mill piece of correspondence. It contains Jefferson’s views about the recently ended War of 1812 and its place in American history.

"This is one of the most important historical collections to reach the market in at least a decade if not a generation," Nathan Raab, the vice president of Philadelphia-based autograph dealer the Raab Collection, which recently acquired the Crawford documents and put the letter up for sale for $325,000, tells Smithsonian.com.

The letter was written a few months after the signing of the Treaty of Ghent, which ended the War of 1812. That conflict, caused by simmering tensions between the young United States and Great Britain, is not well understood by most Americans.

The conflict is most remembered for the United States' early military blunders, the sack and burning of the White House by the British and Andrew Jackson’s defense of New Orleans. In Canada, however, the war is considered one of the founding events in that nation, with British and First Nations forces repulsing American attempts to annex Ontario and Quebec, a battle that Jefferson thought would be a cake walk.

Despite failing to capture “Upper Canada,” the letter, previouly published by the Library of Congress, shows Jefferson was enthusiastic over the war’s outcome. “As in the Revolutionary War, [the British] conquests were never more than of the spot on which their army stood, never extended beyond the range of their cannon shot. We owe to their past follies and wrong the incalculable advantage of being made independent of them,” Jefferson wrote in the letter, reports Perry Chiaramonte at Fox News.

According to the Raab Collection, Jefferson also discusses several other topics, writing that the burning of the White House was “more disgraceful to England than to us.” The defeat of Napoleon in April 1814, which Crawford observed from France and wrote to Jefferson about, also loomed large since it freed up Britain’s military to focus on its former colony. “[Napoleon’s] downfall was illy timed for us,” writes Jefferson. “It gave to England an opportunity to turn full handed on us, when we were unprepared. No matter. We can beat her on our own soil…”

Jefferson also talks about the Battle of New Orleans, which that took place after the peace treaty had been signed, saying that the engagement led by Andrew Jackson still served a purpose. “It proved. . . that New Orleans can be defended both by land & water; that the Western country will fly to its relief . . . that our militias are heroes when they have heroes to lead them on,” he writes.

In late May, the Raab Collection put the other four-page document written from Jefferson to Crawford in 1816 on the market for $375,000. In it, Jefferson rebukes the Bank of the United States and the financial system that had been proposed by Alexander Hamilton, arguing his economics would lead to “licentious commerce and gambling speculations for a few, with eternal war for the many” as opposed to his vision for the economy which would lead to “restricted commerce, peace, and steady occupations for all.”

“In many ways, this letter is the great American debate, and it is remarkable that it survived in the hands of the family for so many years,” Raab tells FoxNews.com.