“Our toast in general is,—Magna Charta, the British Constitution,—PITT and Liberty forever!”

Had some of his Majesty's unhappy predecessors trusted less to the commentary of their Ministers, and been better read in the text itself, the glorious Revolution might have remained only possible in theory, and their fate would not now have stood upon record, a formidable example to all their successors.
Speech in the House of Lords (22 January 1770), quoted in William Pitt, The Speeches of the Right Honourable the Earl of Chatham in the Houses of Lords and Commons: With a Biographical Memoir and Introductions and Explanatory Notes to the Speeches (London: Aylott & Jones, 1848), p. 98.

Speech in the Speaker's Courtyard of Parliament for his 80th birthday ceremony (25 July 1928), quoted in The Times (26 July 1928), p. 16
Lord President of the Council

Letter to Abigail Adams (17 July 1775)
1770s
Source: Letters of John Adams, Addressed to His Wife

Speech before the Chamber of Commerce, Elmira, New York (3 May 1907); published in Addresses and Papers of Charles Evans Hughes, Governor of New York, 1906–1908 (1908), p. 139

This instant about two thousand liberty boys are swearing and swaggering by with large sticks
(from vol 2, letter 67: 6 Jun 1780, to J___ S___ esq).

Speech at Edwardsville, Illinois (11 September 1858); quoted in Lincoln, Abraham; Mario Matthew Cuomo, Harold Holzer, G. S. Boritt, Lincoln on Democracy http://books.google.de/books?id=8bWmmyJEMZoC&pg=PA128 (Fordham University Press, September 1, 2004), 128. .
Variant of the above quote: What constitutes the bulwark of our own liberty and independence? It is not our frowning battlements, our bristling sea coasts, our army and our navy. These are not our reliance against tyranny All of those may be turned against us without making us weaker for the struggle. Our reliance is in the love of liberty which God has planted in us. Our defense is in the spirit which prizes liberty as the heritage of all men, in all lands everywhere. Destroy this spirit and you have planted the seeds of despotism at your own doors. Familiarize yourselves with the chains of bondage and you prepare your own limbs to wear them. Accustomed to trample on the rights of others, you have lost the genius of your own independence and become the fit subjects of the first cunning tyrant who rises among you.
Fragment of Speech at Edwardsville, Ill., September 13, 1858; quoted in Lincoln, Abraham; The Writings of Abraham Lincoln V05 http://www.classic-literature.co.uk/american-authors/19th-century/abraham-lincoln/the-writings-of-abraham-lincoln-05/ebook-page-05.asp) p. 6-7
1850s
Context: What constitutes the bulwark of our own liberty and independence? It is not our frowning battlements, our bristling sea coasts, the guns of our war steamers, or the strength our gallant and disciplined army? These are not our reliance against a resumption of tyranny in our fair land. All of those may be turned against our liberties, without making us weaker or stronger for the struggle. Our reliance is in the love of liberty which God has planted in our bosoms. Our defense is in the preservation of the spirit which prizes liberty as the heritage of all men, in all lands, everywhere. Destroy this spirit, and you have planted the seeds of despotism around your own doors. Familiarize yourselves with the chains of bondage and you are preparing your own limbs to wear them. Accustomed to trample on the rights of those around you, you have lost the genius of your own independence, and become the fit subjects of the first cunning tyrant who rises.

Speech to the National Press Club (19 September 1975) http://www.margaretthatcher.org/document/102770
Leader of the Opposition
Context: In every generation there comes a moment to choose, and for too long we've chosen the soft option. And it's brought us pretty low. There are some signs now that our people are prepared to make the tough choice and to follow the harder road. We're still the same people that have fought for freedom, and won, and the spirit of adventure, the inventiveness, the determination are still strands in our character. We may suffer from a British sickness now, but we have a British constitution and it's still sound, and we have British hearts and a British will to win through. I believe in Britain. I believe in the British people. I believe in our future.

Speech, United States Senate (11 March 1850).
Context: It is true, indeed, that the national domain is ours. It is true that it was acquired by the valor and with the wealth of the whole nation. But we hold no arbitrary authority over it. We hold no arbitrary authority over anything, whether lawfully acquired or seized by usurpation. The constitution regulates our stewardship; the constitution devotes the domain to union, to justice, to defense, to welfare and to liberty.
But there is a higher law than the Constitution, which regulates our authority over the domain, and devotes it to the same noble purposes.

Source: Greybeard (1964), Chapter 4 (p. 112)