23 June, 1863.
I have the honor to return herewith the consular despatches which accompanied your letter of the 16th ultimo.
The suggestion of our commercial agent at Belize, in regard to the traffic carried on by the insurgents via Matamoras, deserves especial consideration. It appears to me some measures should be taken to interdict this trade; for as now permitted, the great purposes and ends of the Blockade are measurably defeated. That the clearances which these vessels have ostensibly for Matamoras, as Mr. Leas remarks, were subterfuges — decoys to cover up the true designs and purposes of the parties, which are to introduce, through French and other agencies, contraband of war into the hands of our enemies — is notorious.
It is desirable that the fraudulent practices mentioned by Mr. Leas should be discontinued, and I trust the attention of the British and Mexican Governments is called to them.
It seems to me some measures should be taken in concert with Mexico, by which illicit traffic with the rebels, by the way of the Rio Grande, may be prevented; or if that Government will not come into an arrangement, then by some legitimate means assert our right to carry into effect an efficient and thorough blockade of that river. The trade of Matamoras has nominally increased an hundred fold since the blockade of the insurgent States was instituted. Admiral Bailey informs the Department that over two hundred vessels are off the mouth of the Rio Grande, when ordinarily there are but six or eight. Our rights as a nation ought not to be sacrificed because a new question has arisen that has not heretofore been adjudicated or settled by diplomatic arrangement. Because the Rio Grande is a neutral highway, it is not to be used to our injury, — yet we know such to be the fact, and it seems to me some effectual steps should be taken to correct the evil. It can be done, I apprehend, in a manner satisfactory to both countries, and a principle be established that will be conformable to international law. I must ask you to excuse me for pressing this subject upon your consideration.
I would also invite your special attention to that portion of the despatch which refers to a mail arrangement, by which Captain Lombard, of the schooner “Robert Anderson,” with British papers, was to run a regular mail from Belize to Matamoras for the “Confederate Government.” Would it not be well to inform the Secretary of War of the facts in relation to “Vallez,” at New Orleans, that General Banks may be apprized of the schemes and purposes of that gentleman?
I am, respectfully,
Your Obd't Serv't
Secty. of Navy.
Hon. Wm. H. Seward,
Secty. of State.
SOURCE: Gideon Welles, Diary of Gideon Welles, Secretary of the Navy Under Lincoln and Johnson, Vol. 1: 1861 – March 30, 1864, p. 388-9