“The majority falls prey to the delusion—popular in some circles—that ordinary people are too careless and stupid to own guns, and we would be far better off leaving all weapons in the hands of professionals on the government payroll. But the simple truth—born of experience—is that tyranny thrives best where government need not fear the wrath of an armed people.”

First attributed to Jefferson in 1945, this does not appear in any known Jefferson document. When governments fear the people, there is liberty... http://wiki.monticello.org/mediawiki/index.php/When_governments_fear_the_people,_there_is_liberty...(Quotation), Thomas Jefferson Encyclopedia. It first appears in 1914, in [Barnhill, John Basil, John Basil Barnhill, Indictment of Socialism No. 3, Barnhill-Tichenor Debate on Socialism, http://debs.indstate.edu/b262b3_1914.pdf, PDF, 2008-10-16, 1914, National Rip-Saw Publishing, Saint Louis, Missouri, p. 34]
Misattributed
Variant: Where the people fear the government you have tyranny. Where the government fears the people you have liberty.

Neither Democrats, Nor Dictators: Anarchists (1926)
Context: The "government of all the people", if we have to have government, can at best be only the government of the majority. And the democrats, whether socialists or not, are willing to agree. They add, it is true, that one must respect minority rights; but since it is the majority that decides what these rights are, as a result minorities only have the right to do what the majority wants and allows. The only limit to the will of the majority would be the resistance which the minorities know and can put up. This means that there would always be a social struggle, in which a part of the members, albeit the majority, has the right to impose its own will on the others, yoking the efforts of all to their own ends.
And here I would make an aside to show how, based on reasoning backed by the evidence of past and present events, it is not even true that where there is government, namely authority, that authority resides in the majority and how in reality every "democracy" has been, is and must be nothing short of an "oligarchy" – a government of the few, a dictatorship. But, for the purposes of this article, I prefer to err on the side of the democrats and assume that there can really be a true and sincere majority government.
Government means the right to make the law and to impose it on everyone by force: without a police force there is no government.

This appears to be a manufactured quote for a PBS documentary on the American Revolution, created by condensing, rewriting, and paraphrasing portions of a lengthy letter James Madison wrote to Thomas Jefferson on 17 October 1788 http://oll.libertyfund.org/?option=com_staticxt&staticfile=show.php%3Ftitle=1937&chapter=118854&layout=html&Itemid=27, about the need for a Bill of Rights and the danger of an establishment of religion. The resulting "quote" profoundly changed the import of what Madison was trying to say and uses modern English. The phrases "biggest danger" and "tyranny of the majority" aren't even in the original letter. The relevant portions of the original letter are (italics in the original; bold added for emphasis):<blockquote>"… In Virginia I have seen the bill of rights violated in every instance where it has been opposed to a popular current. Notwithstanding the explicit provision contained in that instrument for the rights of Conscience, it is well known that a religious establishment would have taken place in that State, if the Legislative majority had found as they expected, a majority of the people in favor of the measure; and I am persuaded that if a majority of the people were now of one sect, the measure would still take place and on narrower ground than was then proposed, notwithstanding the additional obstacle which the law has since created. Wherever the real power in a Government lies, there is the danger of oppression. In our Governments the real power lies in the majority of the Community, and the invasion of private rights is chiefly to be apprehended, not from acts of Government contrary to the sense of its constituents, but from acts in which the Government is the mere instrument of the major number of the Constituents. This is a truth of great importance, but not yet sufficiently attended to; and is probably more strongly impressed on my mind by facts, and reflections suggested by them, than on yours which has contemplated abuses of power issuing from a very different quarter. Wherever there is an interest and power to do wrong, wrong will generally be done, and not less readily by a powerful & interested party than by a powerful and interested prince. …"</blockquote>
Misattributed

I Ask You—What Price Freedom? Answers, 24 October 1936.
Reproduced in The Collected Essays of Sir Winston Churchill, Vol I, Churchill at War, Centenary Edition (1976), Library of Imperial History, p. 360.
The 1930s
Context: We live in a country where the people own the Government and not in a country where the Government owns the people. Thought is free, speech is free, religion is free, no one can say that the Press is not free. In short, we live in a liberal society, the direct product of the great advances in human dignity, stature and well-being which will ever be the glory of the nineteenth century.

Jeff Cooper's Commentaries, vol. 4, no. 16, December, 1996

Nobel lecture (2001)

Source: The Boat of a Million Years (1989), Chapter 18 “Judgment Day”, Section 15 (p. 396)

Letter to W.T. Barry http://press-pubs.uchicago.edu/founders/documents/v1ch18s35.html (4 August 1822), in The Writings of James Madison (1910) edited by Gaillard Hunt, Vol. 9, p. 103; these words, using the older spelling "Governours", are inscribed to the left of the main entrance, Library of Congress James Madison Memorial Building.
1820s