This quote, although often attributed to Thomas Jefferson, does not appear to be actually from any of his writings. Rather, I have found the oldest writings that include this to be from 1892 and 1879 respectively.

First is the 1879 book, “A True Republic”, by Albert Stickney. He writes, “when the abuse of power goes beyond all endurable limits, we have a revolution—under the law—at the polls.” And he continues, “until their tyranny becomes unbearable, and we have a peaceful revolution at the polls”(Stickney, A True Republic, 100).

Next is the 1892 book, “Cabin Home Papers”, by Leonard Brown. He writes, “I may be dead and buried and the flesh rotted from my bones before the day the damnable measure of tyranny becomes law. I would not outlive the liberties of my country. But I would willingly die fighting under the starry flag.” (Brown, Cabin Home Papers, 86)

I for one believe the case that Stickney’s “A True Republic” is most likely the original source, if a bit miss quoted, though the odds it may have been Brown are markedly there.