==Jefferson==
Jefferson used this phrase as early as 1780 as he sought to create an American Empire dedicated to liberty; it would block the growth of the British Empire, which he hated and feared:
:"We shall divert through our own Country a branch of commerce which the European States have thought worthy of the most important struggles and sacrifices, and in the event of peace [ending the American Revolution]...we shall form to the American union a barrier against the dangerous extension of the British Province of Canada and add to the '''Empire of liberty''' an extensive and fertile Country thereby converting dangerous Enemies into valuable friends." - Jefferson to George Rogers Clark, 25 December 1780<ref> See [http://wiki.monticello.org/mediawiki/index.php/Empire_of_liberty online source] </ref> A few weeks after leaving the White House in 1809 he told his successor James Madison::"we should then have only to include the North [Canada] in our confederacy...and we should have such an empire for liberty as she has never surveyed since the creation: & I am persuaded no constitution was ever before so well calculated as ours for extensive empire & self government." - Jefferson to James Madison, 27 April 1809
==Other dimensions==