TO THE PACIFIC
He compromised the Oregon question with England by the Treaty of 1846, accepting the forty-ninth parallel as the boundary, in spite of the campaign cry of “fifty-four forty or fight.” The same year the Mexican war began, in which American troops overran California and the intervening land.
With the American flag floating over the capital of Mexico, a strong movement began to hold Mexico itself, or at least additional territory. But by the Treaty of Guadalupe-Hidalgo〖H. C., xliii, 289.〗 in 1848 the line was drawn along the Gila River and from its mouth to the Pacific. Agitation for a southern route to the Pacific led to the further acquisition of a zone south of the Gila by the Gadsden Purchase of 1853.
By these annexations between 1846 and 1853 the United States gained over 1,200,000 square miles of territory. Gold was discovered in California in 1848, and unimagined riches in precious metals, timber, and agricultural resources were later revealed in this vast new empire. But most important of all was the fact that the nation had at last made its lodgment on the shores of the Pacific, where it was to be involved in the destiny of that ocean and its Asiatic shores.
The South, deprived of the benefits of these great acquisitions by the compromise of 1850, tried in vain to find new outlets by Cuban annexation. But the Civil War resulting from the rivalries of the expanding sections engrossed the energies of the nation. At the close of that war, Russia, which had given moral support to the North when England and France were doubtful, offered the United States her Alaskan territory and, not without opposition, Secretary Seward secured the ratification of a treaty〖H. C., xliii, 432.〗 in 1867 by which nearly six hundred thousand square miles were added to our domains.
For nearly a third of a century after the Civil War the energies of the Union were poured out in the economic conquest of the vast annexations in its contiguous territory. In 1892 the Superintendent of the Census announced that the maps of population could no longer depict a frontier line bounding the outer edge of advancing settlement. The era of colonization was terminating. The free lands were being rapidly engrossed and the Union was reaching the condition of other settled states.