Thomas Jefferson used a version of the phrase "empire of liberty" on more than one occasion. Two examples are provided below:
... 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 on terms which have been contemplated by some powers 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, December 25, 1780[1]
we should then have only to include the North in our confederacy, which would be of course in the first war, 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, April 27, 1809[2]
