In April, 1817, the governments of Great Britain and the United States came to an important agreement which ensured the neutrality of the great lakes. It was agreed that the naval forces to be maintained upon these inland waters should be confined to the following vessels: on Lakes Champlain and Ontario to one vessel, on the Upper Lakes to two vessels, not exceeding in each case a hundred tons burden and armed with only one small cannon. Either nation had the right to bring the convention to a termination by a previous notice of six months. This agreement is still regarded by Great Britain and the United States to be in existence, since Mr. Secretary Seward formally withdrew the notice which was given for its abrogation in 1864, when the civil war was in progress and the relations between the two nations were considerably strained at times. The next international complication arose out of the seizure of the steamer _Caroline_, which was engaged in 1837 in carrying munitions of war between the United States and Navy Island, then occupied by a number of persons in the service of Mr. Mackenzie and other Canadian rebels. In 1840 the authorities of New York arrested one Macleod on the charge of having murdered a man who was employed on the _Caroline_. The Washington government for some time evaded the whole question by throwing the responsibility on the state authorities and declaring that they could not interfere with a matter which was then within the jurisdiction of the state courts. The matter gave rise to much correspondence between the two governments, but happily for the peace of the two countries the American courts acquitted Macleod, as the evidence was clear that he had had nothing to do with the actual seizing of the _Caroline_; and the authorities at Washington soon afterwards acknowledged their responsibility in such affairs by passing an act directing that subjects of foreign powers, if taken into custody for acts done or committed under the authority of their own government, "the validity or effect whereof depends upon the law of nations, should be discharged." The dissatisfaction that had arisen in the United States on account of the cutting out of the _Caroline_ was removed in 1842, when Sir Robert Peel expressed regret that "some explanation and apology for the occurrence had not been previously made," and declared that it was "the opinion of candid and honourable men that the British officers who executed this transaction, and their government who approved it, intended no insult or disrespect to the sovereign authority of the United States[9]." [9: Hall's _Treatise on International Law_ (3rd ed.), pp. 311--313]