California was really justified, it would be difficult to say. Much clearer light will probably be thrown on this subject by future investigations in the archives of the British and American governments, but thus far little positive evidence has been produced. There is, however, no reason to doubt that President Polk really believed that Great Britain meant to take the province. This conviction was supported by the California correspondence of the newspapers and the reports from Larkin, the United States consul at Monterey. Larkin's suspicions were based mainly on the fact that Great Britain maintained a consulate in California which he believed to be of no use except as a secret agency, and on certain very imperfect proofs that she intended to interfere on behalf of California in the quarrel in which that province was then engaged with the government in Mexico.1

Considerable interest attaches to Polk's utterances which he regarded as "re-asserting Mr. Monroe's doctrine." What is popularly known as the Monroe Doctrine has been set forth in several different forms to meet varying diplomatic emergencies, and has had no exact definition. The constant element of the doctrine appears to be that no European interference in America prejudicial to the interests of the United States shall be permitted.' It

1 Bancroft, California, IV., 590-593; Niles' Register, LXIX., 147, 203, 244; cf. Hittell, California, II., 375-378, 458.

'Cf. Hart, Foundations of Am. Foreign Policy, chap. vii.

is only natural that the assertion of this principle has been, on the whole, more aggressive and more positive with the growth of the strength and prestige of the United States. In the official utterances of Washington and Jefferson the doctrine appears almost purely on its negative side, and emphasizes the policy of keeping clear of European affairs. When the international status of the United States became more clearly defined and more fully established, Monroe added the complementary inhibition against European interference in America. Polk denied that the principle of the balance of power had any application to North America, or that European powers, to maintain it, could be allowed to interfere against the annexation of any independent North American state by the American Union.1 On the other hand, no such annexation by a European power could be allowed, and he favored the military occupation of Yucatan, in response to its request for protection from the Indians, in order to prevent the acquisition of a claim upon that country by any nation of Europe that might be disposed to give it the desired help. Polk declared also "that no future European colony or dominion shall, with our consent, be planted or established on any part of the North American continent.” He could scarcely have meant this to exclude the extension of the settled area in British America by colonists of that

1 Richardson, Messages and Papers, IV., 398.

2 Ibid., 581-583; cf. Polk, MS. Diary, April 25, May 6, 1848.

nationality; but he undoubtedly meant the statement to apply to European colonization in the Spanish-American states, whether with or without their consent. Monroe's formulation of the doctrine had not gone so far.

In a communication of October 17, 1845, Black reported the result of his inquiry.' He had put to the Mexican government as coming from the president of the United States the question "whether they would receive an envoy from the United States, intrusted with full power to adjust all questions in dispute between the two governments. In reply he had been informed that, though the Mexican nation had been deeply injured by the acts of the United States in dealing with Texas, it was disposed to receive a "commissioner" who might come "with full powers from his government to settle the present dispute in a peaceable, reasonable, and honorable manner." The Mexican government expressed the hope that the commissioner would be so discreet and reasonable as "to calm as much as possible the just irritation of the Mexicans. It was stated as an indispensable condition of the renewal of diplomatic relations that the whole of the United States naval force lying in front of Vera Cruz should be recalled. This answer reached Washington November 6, and on the next day the president and secretary of state, in a conference, agreed that a minister should be ap1 House Exec. Docs., 30 Cong., 1 Sess., VII., No. 60, pp. 13-17.

pointed and despatched to Mexico at once.1 To forestall foreign interference, it was to be done secretly. The removal of the fleet from Vera Cruz had been ordered by Commodore Conner as soon as the wishes of the Mexican government were made known to him.2

Instructions to Slidell were prepared as promptly as possible, read and amended in the cabinet, and finally agreed to unanimously November 8, 1845. The principal objects of the mission were to be to counteract foreign influences against the United States in Mexico, and to restore the old, peaceful relations of the two countries. It was suggested that the wretched internal condition of Mexico and the misunderstandings of its government with the ministers of Great Britain and France just then made the moment propitious. The considerations in favor of an American policy on the basis of the Monroe Doctrine were emphasized.*

Slidell was to give his attention first to the claims of citizens of the United States against the Mexican government which remained unsatisfied. The history of the claims was sketched, and the question as to how they could be settled amicably was considered. All the world knew, it was observed, that Mexico could not then pay money; and unless the

1 Polk, MS. Diary, November 7, 1845.

2 House Exec. Docs., 30 Cong., 1 Sess., VII., No. 60, p. 19. 3 For the text of the instructions, see Buchanan to Slidell, November 10, 1845, in Senate Docs., 30 Cong., 1 Sess., VII., No. 52, pp. 71-80; cf. Polk, MS. Diary, November 10, 1845.

United States government assumed the debt the claimants could not get their dues. But the settlement of the boundary question, which had been reserved by the terms of annexation agreed on with Texas, might be so directed as to place the burden on that government without doing injury to Mexico.

The history of the boundary controversy was then recited, and an effort was made to show that the Rio Grande was the proper line between Texas and Mexico from its mouth to El Paso. This contention was based on the fact that the jurisdiction of Texas had been extended beyond the Nueces, and that the country west of that river had been represented in the Texas congress and the convention which had acted on the subject of annexation. It was alleged also that ancient Louisiana extended to the Rio Grande, but it was not claimed that the jurisdiction of Texas had been established up to that river. It was conceded that Mexico had a better claim to New Mexico than to the disputed part of the lower Rio Grande valley; but that province was far away from the Mexican capital and difficult to defend from the Indians, and much of it was within limits also claimed by Texas. It might, therefore, if it remained Mexican, become a source of ill-feeling between those who, it was hoped, were destined to be friends. But this danger would be removed, and Mexico would be saved expense and trouble, by so fixing the boundary as to leave New