To the Senate and House of Representatives of the United States:
In compliance with the request of the House of Representatives expressed in their resolution of the 5th instant, I proceed to give such information as is possessed of the effect of gunboats in the protection and defense of harbors, of the numbers thought necessary, and of the proposed distribution of them among the ports and harbors of the United States.
Under present circumstances, and governed by the intentions of the Legislature as manifested by their annual appropriations of money for the purposes of defense, it has been concluded to combine, first, land batteries furnished with heavy cannon and mortars, and established on all the points around the place favorable for preventing vessels from lying before it; second, movable artillery, which may be carried, as occasion may require, to points unprovided with fixed batteries; third, floating batteries, and fourth, gunboats which may oppose an enemy at his entrance and cooperate with the batteries for his expulsion.
On this subject professional men were consulted as far as we had opportunity. General Wilkinson and the late General Gates gave their opinions in writing in favor of the system, as will be seen by their letters now communicated. The higher officers of the Navy gave the same opinions in separate conferences, as their presence at the seat of Government offered occasions of consulting them, and no difference of judgment appeared on the subject. Those of Commodore Barron and Captain Tingey, now here, are recently furnished in writing, and transmitted herewith to the Legislature.
The efficacy of gunboats for the defense of harbors and of other smooth and inclosed waters may be estimated in part from that of galleys formerly much used but less powerful, more costly in their construction and maintenance, and requiring more men. But the gunboat itself is believed to be in use with every modern maritime nation for the purposes of defense. In the Mediterranean, on which are several small powers whose system, like ours, is peace and defense, few harbors are without this article of protection. Our own experience there of the effect of gunboats for harbor service is recent. Algiers is particularly known to have owed to a great provision of these vessels the safety of its city since the epoch of their construction. Before that it had been repeatedly insulted and injured. The effect of gunboats at present in the neighborhood of Gibraltar is well known, and how much they were used both in the attack and defense of that place during a former war. The extensive resort to them by the two greatest naval powers in the world on an enterprise of invasion not long since in prospect shews their confidence in their efficacy for the purposes for which they are suited. By the northern powers of Europe, whose seas are particularly adapted to them, they are still more used. The remarkable action between the Russian flotilla of gunboats and galleys and a Turkish fleet of ships of the line and frigates in the Liman Sea in 1788 will be readily recollected. The latter, commanded by their most celebrated admiral, were completely defeated, and several of their ships of the line destroyed.
From the opinions given as to the number of gunboats necessary for some of the principal seaports, and from a view of all the towns and ports from Orleans to Maine, inclusive, entitled to protection in proportion to their situation and circumstances, it is concluded that to give them a due measure of protection in times of war about 200 gunboats will be requisite.
According to first ideas the following would be their general distribution, liable to be varied on more mature examination and as circumstances shall vary; that is to say:
To the Mississippi and its neighboring waters, 40 gunboats.
To Savannah and Charleston, and the harbors on each side from St. Marys to Currituck, 25.
To the Chesapeake and its waters, 20.
To Delaware Bay and River, 15.
To New York, the Sound, and waters as far as Cape Cod, 50.
To Boston and the harbors north of Cape Cod, 50.
The flotillas assigned to these several stations might each be under the care of a particular commandant, and the vessels composing them would in ordinary be distributed among the harbors within the station in proportion to their importance.
Of these boats a proper proportion would be of the larger size, such as those heretofore built, capable of navigating any seas and of reenforcing occasionally the strength of even the most distant ports when menaced with danger. The residue would be confirmed to their own or the neighboring harbors, would be smaller, less furnished for accommodation, and consequently less costly. Of the number supposed necessary, 73 are built or building, and the 127 still to be provided would cost from $500,000 to $600,000. Having regard to the convenience of the Treasury as well as to the resources for building, it has been thought that the one-half of these might be built in the present year and the other half the next. With the Legislature, however, it will rest to stop where we are, or at any further point, when they shall be of opinion that the number provided shall be sufficient for the object.
At times when Europe as well as the United States shall be at peace it would not be proposed that more than six or eight of these vessels should be kept afloat. When Europe is in war, treble that number might be necessary, to be distributed among those particular harbors which foreign vessels of war are in the habit of frequenting for the purpose of preserving order therein. But they would be manned in ordinary, with only their complement for navigation, relying on the seamen and militia of the port if called into action on any sudden emergency. It would be only when the United States should themselves be at war that the whole number would be brought into active service, and would be ready in the first moments of the war to cooperate with the other means for covering at once the line of our seaports. At all times those unemployed would be withdrawn into places not exposed to sudden enterprise, hauled up under sheds from the sun and weather, and kept in preservation with little expense for repairs or maintenance.
It must be superfluous to observe that this species of naval armament is proposed merely for defensive operation; that it can have but little effect toward protecting our commerce in the open seas, even on our own coast; and still less can it become an excitement to engage in offensive maritime war, toward which it would furnish no means.
Thomas Jefferson, Special Message Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/202568