To the Senate and House of Representatives.
I lay before Congress copies of certain documents which remain in the department of state. They prove that at a recent period, whilst the U. States, notwithstanding the wrong sustained by them, ceased not to observe the laws of peace and neutrality towards G. Britain; and in the midst of amicable professions and negotiations on the part of the British government, through her public minister here, a secret agent of that government was employed in certain states, more especially at the seat of government (Boston) in Massachusetts, in fermenting disaffection to the constituted authorities of the nation, and in intrigues with the disaffected, for the purpose of bringing about resistance to the laws; and eventually in concert with a British force, of destroying the Union and forming the Eastern part thereof into a political connection with G. Britain.
The message from Madison accompanied the papers purchased for $50,000 on February 7, 1812 from John Henry pursuant to the agreement negotiated with the Comte de Crillon, the French confidence man. Madison waited to hear that John Henry had sailed for France before delivering the papers to Congress. The papers described Henry's mission in 1808 in New England gathering information for the British. Madison wanted to show a grand conspiracy of the British acting in combination with the New England Federalists or as he termed them the "Eastern Junto". He hoped to use the papers to arouse American public opinion against the British in order to justify the commencement of war. This is telling in that it indicates that public opinion was still unsettled as to whether to go to war. The French Ambassador, Serurier, put it this way:In addition to the effect which the discovery of such a procedure ought to have on the public councils, it will not fail to render more dear to the hearts of all good citizens that happy union of these states, which under Divine Providence, is the guarantee of their liberties, their safety, their tranquillity and their prosperity.James Madison
"The American people recall to me the son of Ulysses, on the rock of Calypso's ilse; uncertain, irresolute, he knows to which of his passions to yield, when Minerva, flinging him into the sea, fixes, his fate, leaving him no other choice than to overcome by his courage and strength the terrible elements she gives him for any enemy"
Henry's papers turned out not to be very compelling as a basis for war or explosive in terms of its contents. They showed that Henry had visited different places, read various newspapers and communicated what he learned back to the British. The papers can be found here. Henry Adams in his inimitable style describes it the delivery of the papers to Congress in this way:
When John Henry's letters were read in Congress, March 9, 1812, the Federalists for a moment felt real alarm, for they knew not what Henry might have reported; but a few minutes of examination showed them that, as far as they were concerned, Henry had taken care to report nothing of consequence. That he came to Boston as a British agent was hitherto unknown to the Federalists themselves, and the papers showed that he never revealed his secret character to them. His letters were hardly more compromising than letters, essays, and leading articles, sermons, orations, and addresses that had been printed again and again in every Federalist paper in Boston and New York. Here and there they contained mysterious asterisks, but no other sign of acquaintance with facts worth concealing... the letters which he sold as his own were not copies but paraphrases of the originals; the mysterious asterisks were introduced merely to excite curiosity; and except the original instructions of Sir James Craig and the recent letter from Lord Liverpool's secretary, showing that in view of an expected war Henry had been employed as a s secrete agent to obtain political information by the governor-general, and that his reports had been sent to the Colonial office, nothing in these papers compromised any one except Henry himself. As for the British government, since war was to be waged with it in any case for other reasons, these papers distracted attention from the true issue.
(Adams, Henry, History of the United States of America during the Administration of James Madison (New York: The Library of America, 1986), 419-4120