Executive reports repeatedly acknowledged this fact. In 1839 "a careful revision of these laws" is recommended by the President, in order that "the integrity and honor of our flag may be carefully preserved."[44] In June, 1841, the President declares: "There is reason to believe that the traffic is on the increase," and advocates "vigorous efforts."[45] His message in December of the same year acknowledges: "That the American flag is grossly abused by the abandoned and profligate of other nations is but too probable."[46] The special message of 1845 explains at length that "it would seem" that a regular policy of evading the laws is carried on: American vessels with the knowledge of the owners are chartered by notorious slave dealers in Brazil, aided by English capitalists, with this intent.[47] The message of 1849 "earnestly" invites the attention of Congress "to an amendment of our existing laws relating to the African slave-trade, with a view to the effectual suppression of that barbarous traffic. It is not to be denied," continues the message, "that this trade is still, in part, carried on by means of vessels built in the United States, and owned or navigated by some of our citizens."[48] Governor Buchanan of Liberia reported in 1839: "The chief obstacle to the success of the very active measures pursued by the British government for the suppression of the slave-trade on the coast, is the _American flag_. Never was the proud banner of freedom so extensively used by those pirates upon liberty and humanity, as at this season."[49] One well-known American slaver was boarded fifteen times and twice taken into port, but always escaped by means of her papers.[50] Even American officers report that the English are doing all they can, but that the American flag protects the trade.[51] The evidence which literally poured in from our consuls and ministers at Brazil adds to the story of the guilt of the United States.[52] It was proven that the participation of United States citizens in the trade was large and systematic. One of the most notorious slave merchants of Brazil said: "I am worried by the Americans, who insist upon my hiring their vessels for slave-trade."[53] Minister Proffit stated, in 1844, that the "slave-trade is almost entirely carried on under our flag, in American-built vessels."[54] So, too, in Cuba: the British commissioners affirm that American citizens were openly engaged in the traffic; vessels arrived undisguised at Havana from the United States, and cleared for Africa as slavers after an alleged sale.[55] The American consul, Trist, was proven to have consciously or unconsciously aided this trade by the issuance of blank clearance papers.[56]