Tom DiLorenzo on how the Louisiana Purchase agitated New England secessionists

Jefferson's Louisiana Purchase infuriated the New England Federalists, who wanted America to remain as "ethnically pure" as possible.  Most of them agreed with William Smith Shaw that "the grand cause of all our present difficulties may be traced... to so many hordes of foreigners immigrating to America."  Given such strong feelings about ethnic purity, for New Englanders the Louisiana Purchase, which encouraged the settlement of even more "horders of foreigners" in the United States, was intolerable.  Josiah Quincy was so outraged that he believed the only recourse for the New England states was secession.  The Louisiana Purchase meant that "the bonds of this Union are virtually dissolved; that the States which compose it are free from their moral obligation; and that, as with be the right of all, so it will be the duty of some, to prepare definitely for a separation, amicably if they can, violently if they must."

~ Tom DiLorenzo, The Real Lincoln, p. 96

Map of Louisiana Purchase
1904