Thomas Jefferson said the following in a letter to William Stephens Smith on November 13, 1787. The exact quote is:
“And what country can preserve its liberties if their rulers are not warned from time to time that their people preserve the spirit of resistance? Let them take arms. The remedy is to set them right as to facts, pardon and pacify them. What signify a few lives lost in a century or two? The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants. It is its natural manure.”
This quote is often cited as an expression of Jefferson’s belief in the importance of individual liberty and the need for citizens to be vigilant against the encroachment of government power. The phrase “the tree of liberty must be refreshed from time to time with the blood of patriots and tyrants” has become particularly well-known as a statement of the importance of defending freedom and the willingness to sacrifice for it.