Often attributed to Jefferson, no original source for this has been found in his writings, and the earliest established source for similar remarks are those of John Philpot Curran in a speech upon the Right of Election (1790), published in Speeches on the late very interesting State trials (1808):
: "It is the common fate of the indolent to see their rights become a prey to the active. The condition upon which God hath given liberty to man is eternal vigilance; which condition if he break, servitude is at once the consequence of his crime and the punishment of his guilt."
*In a biography of Major General James Jackson published in 1809, author Thomas Charlton wrote that one of the obligations of biographers of famous people is
:"fastening upon the minds of the American people the belief, that 'the price of liberty is eternal vigilance' " (in Thomas Usher Pulaski Charlton, The life of Major General James Jackson https://books.google.com.br/books?id=cEcSAAAAYAAJ&pg=PA85&redir_esc=y#v=onepage&q&f=false; F.Randolph, & Co., 1809, p. 85).
Misattributed
Variant: "Eternal vigilance is the price of liberty; power is ever stealing from the many to the few" (from a speech by Wendell Phillips at the Massachusetts Anti-Slavery Society on January 28, 1852; quoted by John Morley, ed., The Fortnightly https://books.google.com.br/books?id=VfjRAAAAMAAJ&pg=PA67&lpg=PA67&dq=%E2%80%9CEternal+vigilance+is+the+price+of+liberty.%E2%80%9D+phillips+speech+anti-slavery&source=bl&ots=H2f8ckIw9o&sig=EukDrduBdK-oQSeY_Gf-VFQ6M54&hl=en&ei=SaxmTN-0H4P98AbioIi0BA&sa=X&oi=book_result&ct=result&redir_esc=y#v=onepage&q=%E2%80%9CEternal%20vigilance%20is%20the%20price%20of%20liberty.%E2%80%9D%20phillips%20speech%20anti-slavery&f=false, Volume VIII, Chapman and Hall, 1870, p. 67).
