The general Anglo-American claims conven tion of 1853, under which it was submitted, also provided for arbitration of other claims of American citizens resulting in an award in the McLeod case and important decisions regard ing fishery rights.
For nearly two decades before the Ameri can Civil War, American foreign policy relat ing to the Caribbean was largely influenced or dominated by apprehensive fears of American slaveholders that the safety of slavery in the Southern States might be endangered by the effects of emancipation in the British West Indies, through its influence upon neighboring islands and upon general British policy in the entire region, especially in Cuba. After 1840, more or less influenced by floating rumors, the United States became somewhat apprehensive of possible British annexation of Cuba as se curity for Spanish loans held by British sub jects, and issued a warning announcement of American policy against such a transfer. In 1848 it was watchful of conditions in Yucatan and along the Nicaraguan Isthmian transit route which invited British interference and occu pation. It was also influenced by complaints submitted by Venezuela in 1841 and thereafter concerning British extension in Guiana and emi gration to Venezuela which caused apprehension of British design of annexation there. In 1843, the immediate annexation of Texas was urged to counteract British designs against slavery in terests; and at the same time there was a fear that its annexation might provoke Great Britain to occupy Cuba. Later rumors of the possi bility of an exchange of Cuba in payment of Spanish debts or for Gibraltar doubtless in fluenced Polk's negotiations for Cuba in 1848 and thereafter.
In the same decade, the American govern ment also became watchful to prevent possible sources of Anglo-American conflict in the Pa cific. At the same time, British relations with China opened the way for a successful negotia tion of an American treaty with China in 1844. Meantime, in 1846, the Oregon boundary ques tion, which was an increasing source of danger ous tension and brief bluster, was settled by the American acceptance of the 49th parallel, but reserving to the British all of Vancouver Is land — a geographical exception which con tained the germ of another boundary dispute, finally settled in 1872.
Since 1841, the conditions of international amity had steadily improved, although certain sections of the United States were influenced by Irish limmigrants who nursed traditional enmity to England, preached the antipathy aroused after 1842 by the agitations of O'Connell and the °Young Ireland Party" and by subsequent Irish misfortune, accepted the opportunity to become an active factor in American politics, and were ready to fire a hemisphere to boil their potatoes.
After the subsidence of the brief bluster over the Oregon question, and even in the face of threatened complications in Central America, safe leaders felt the importance of peaceful ad justment based on mutual interests. A tend ency in favor of a change of American foreign policy with a view to closer co-operation with Great Britain appeared about 1850. It was practically illustrated by the official action of Secretary Clayton in 1849 in authorizing Ban croft invite Great Britain to accede to the isthmian guarantee assumed by the United States in the treaty with New Granada, and in entering into negotiations with Bulwer in 1850 for neutrality of a prospective canal across Cen tral America, and also by the official action of both Clayton and Webster in co-operating with Great Britain and France to secure peace be tween the Dominican Republic and Hayti. An opposite tendency is shown, however, in Web ster's later action in declining in 1852 to accede to the proposed tripartite arrangement dis claiming designs on Cuba — an idea which was probably suggested to Lord Malmesbury by the principle of the Clayton-Bulwer Treaty.
In negotiating the Central American canal question, Secretary Clayton, practical states man, was actuated largely by a practical pur pose to avoid a dangerous situation to facilitate the completion of a great enterprise. To secure the withdrawal of Great Britain from territorial occupation against which American sentiment was fixed and irreversible he was willing to share with her jointly the political control and use of the canal, with a guarantee of neutrality based on the doctrine of international freedom of transit. The re sult was the famous Clayton-Bulwer Treaty of 1850 which guaranteed the integrity and in dependence of Central American territory and prepared the way for the extinguishment of any British claim of sovereignty or protectorate over the Mosquito Indians along the coast of Nicaragua—a claim which was finally termi nated by the English treaty negotiated by Wyke with Nicaragua in January 1860.