One of the most hotly contested issues of the time of Whitman's poetic apprenticeship in the late 1840's and 50's was territorial expansion. To many it seemed inevitable that lands to the west of the Missisippi-- claimed by Mexico, England, and a host of American Indian tribes-- should eventually be settled by Americans. In 1845, John O'Sullivan, editor of the influential Democratic Review, coined the phrase "Manifest Destiny" to describe this vision of a United States stretching from Atlantic to Pacific. Yet anti-slavery activists and Democrats, whose belief in federal power was threatened by the South, were opposed to any expansionist move that would add new slave-holding states to the Union and thereby upset the fragile balance of power between North and South. Once the Oregon territorial boundary was settled by a treaty with Great Britain, this conflict settled on Texas. Having declared their independence from Mexico in 1836, a number of Texans sought annexation by the U.S., and got it in 1845. For the Republic of Mexico, this constituted an act of aggression against what their sovereign territory.

War broke out early in 1846, as U.S. general Zachary Taylor moved troops into Texas, and by September Taylor had taken the Mexican city of Monterrey. Meanwhile, other American armies had occupied San Francisco and Santa Fe, realizing President James K. Polk's dream of a route to California. By the end of 1847, General Winfield Scott's troops occupied the capital, Mexico City. As an end to the war was negotiated, the Mexican government had little choice but to cede nearly half of its northern territories--some 850,000 square miles-- to the U.S. for a bargain price (see enlargement of map above). The Treaty of Guadalupe Hidalgo added the vast lands of New Mexico and California to the U.S., but left a dark legacy of distrust of los yanquis in Mexico. The Mexican War provoked a good deal of enthusiastic war-mongering among average citizens in the U.S., although many prominent writers and politicians lamented that the war was just the kind of show of brute force they had always detested among the European powers.  Renewed sectional conflict, however, soon dominated public discussion once again.

Whitman knew O'Sullivan, and the "Young America" crowd of New York, well. He even published his first short stories in O'Sullivan's Democratic Review.  Like him, Whitman came to support the Free-Soil party, which opposed the expansion of slavery (and, with it, Southern influence). On the other hand, he continued to cherish the vision of a large, ever-expanding nation: he imagined that the Union might eventually expand to include Central America and the Caribbean, and wrote in a newspaper article, "'manifest destiny' certainly points to the speedy annexation of Cuba by the United States."¹ The key to this apparent contradiction lies in Whitman's utopian vision: he personified the American continent as an organic whole. For him, there was a virtue in unifying what had been separated, whether that meant individuals or territories. To his dismay, national politics rarely displayed this kind of virtue-- as the Civil War later proved.