Always check the abandoned boxes in your attic because you never know what you might find.

A family in Mississippi discovered a rare letter from founding father Thomas Jefferson in a box of heirlooms, written to their ancestor, U.S. Ambassador to France William Crawford.

The four-page letter from the former president shows his reaction to the end of the War of 1812, comparing it to the American revolution. He discusses the honor of American independence and rails against the British.

    

The Raab Collection, a Philadelphia dealer of historical documents, is selling the letter for $325,000 on behalf of the family.

“The historical importance of this letter blew my mind,” Nathan Raab, the vice president of The Raab Collection, told CNN. “When you read it, you feel like you’re sitting next to Thomas Jefferson, getting his unfiltered thoughts.”

The letter is Jefferson’s first reaction to the signing of the Treaty of Ghent, written at his Monticello home on Valentine’s Day, 1815, according to the Raab Collection which verified its authenticity.

“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,” Jefferson wrote in the letter.

Jefferson also shared his dislike for the British in his letter to Crawford.

“We must sacrifice the last dollar and drop of blood to rid us of that badge of slavery, and it must rest with England alone to say whether it is worth eternal war, for eternal it must be if she holds to the wrong,” he wrote.

The letter was put up for sale on Monday, exactly 190 years after Jefferson died in 1826. Raab said he’s “heard from a number of people” about it, and it continues to be available for purchase.