Four years after the signature of the above treaty with Colombia, and two years after its ratification by the Senate, the United States and Great Britain executed what is popularly known as the Clayton-Bulwer treaty. It is of great importance to understand clearly the circumstances under which this treaty was negotiated. For very obvious reasons, the Isthmus of Panama was for many years the objective point of all canal schemes, but as the engineering difficulties of this route began to be fully appreciated, attention was directed more and more to that through Nicaragua. The occupation by Great Britain, under the assumption of a protectorate, of the territory about the mouth of the San Juan river, which belonged to Nicaragua and Costa Rica, and in which the Atlantic terminus of the canal would fall, was a source of no little uneasiness and perplexity to the United States. In June, 1849, Mr. Hise, charge d'affaires of the United States in Central America, negotiated without the authorization or knowledge of his government, a treaty with Nicaragua which gave the United States exclusive rights in the construction of a canal through the territory of that state.[149] This treaty was not submitted to the Senate, but was made use of in the negotiations that were opened shortly thereafter with Great Britain for the purpose of ousting her from her position of control over the mouth of the San Juan. A few months later, September 28, 1849, Mr. Squier signed with Honduras a treaty which ceded Tiger Island, in the Bay of Fonseca, to the United States, thus giving us a naval station on the Pacific side of the isthmus. This treaty, like that negotiated by Mr. Hise, was unauthorized and never submitted to the Senate.[150] Both treaties were used, however, in bringing England to the signature of the Clayton-Bulwer treaty. This activity in treaty-making was occasioned by the acquisition of California and the rush to the gold fields by way of the isthmus.