Chapter Themes


The decade of the 1840s saw the United States grow by several million immigrants. It also expanded geographically into Texas, New Mexico, California, and Oregon. Although European immigrants during these years included some who came for political or religious reasons, the great majority came to improve their economic conditions. Ireland and the Germanies supplied the largest numbers of these new Americans. Germans tended to settle in the Mississippi and Ohio valleys, many in the cities springing up in those regions. Irish immigrants, numerous by the 1830s, increased dramatically after the great potato famine of 1845. They concentrated mostly in the urban areas of the East, where they provided a source of labor for building the canals and railroads that were connecting the nation's cities. With the rise in immigration, nativism became a significant issue. Anti-Catholicism grew because native-born Protestant Americans feared cheap competition from desperately poor Irish workers. The Irish, in turn, fearing competition from free black labor, were hostile toward blacks and abolitionists.

Both the Irish and the Germans overwhelmingly identified with the Democratic party. It introduced them to national issues, and it made a vigorous effort to convince the immigrants that national expansion was in their interest. Indeed, links with the Far West had to be maintained despite the barrier of the Great Plains and the Rockies. Trading outposts on the California coast were supplied around the Horn and welcomed by Mexican authorities. Similarly trading links were established through the Santa Fe trail and with fur traders in the mountains. Although in the early years of Mexico's independence from Spain, it welcomed contacts with the United States, the tenuousness of its control over far-flung regions like Texas and California carried the seeds of later conflict.

The Mexican government at first encouraged American colonization in Texas. Early indications of trouble caused Mexico to ban further immigration into Texas in 1830 and to forbid the introduction of more slaves from the United States. The effort was unsuccessful. In 1834 President Santa Anna, attempting to establish greater federal control over the Mexican states, was met by revolution and a Texas declaration of independence. Although he won a victory at the Alamo, Santa Anna was later forced to sign a treaty (never ratified) granting independence to Texas.

Attracted by the reputed richness of California and Oregon, settlers went west in great numbers by wagon train to the Promised Land. The Great Plains and the mountains were still perceived as inhospitable, and settlers hastened through them as quickly as possible.

Should the United States annex the independent Lone Star Republic? Settled by slaveholders, Texas would certainly become a slave state. Efforts to deal with the question were inconclusive until James K. Polk, a southern Democrat, announced boldly for "re-annexation" in 1844. By the mid-1840s Manifest Destiny had taken hold in the popular mind. Democrats came to see the acquisition of new territory as a logical complement to the party's policies of low tariffs and opposition to central banking, policies that fostered the factory system. Democrats preferred to provide farmers with land and access to foreign markets. President Polk successfully finessed the British into accepting a compromise in Oregon at the forty-ninth parallel. From Mexico he wanted more. The Slidell mission to negotiate for Texas, New Mexico, and California proved a failure, but Mexico supplied a needed excuse for war by firing on American troops in the disputed land between the Nueces River and the Rio Grande. The Mexican army was far from being a pushover, but American superiority in artillery and leadership gave victory and half of Mexico to the United States.

Many northerners believed that the issue of slavery could not be resolved merely by extending the 36 30 line of the Missouri Compromise to the Pacific. Some opposed slavery on moral grounds. Others feared that an extension of slavery into California and New Mexico would deter settlement by free labor. In 1846 David Wilmot (Democrat, Pennsylvania) sponsored the Wilmot Proviso in Congress prohibiting slavery in any territory to be acquired from Mexico. Constitutional issues were at stake. Slaveholders argued that slaves as property could be carried into whatever territories their owners wished. (Thus, according to Calhoun, the Missouri Compromise was unconstitutional.) On the other hand, northerners pointed out, the Constitution gives Congress the power to make regulations for the territories. The election of 1848 pitted Mexican War hero Zachary Taylor against Lewis Cass of Michigan, an advocate of popular sovereignty. The gold strike in California and the rush of people to the new territory put the question of slavery in the Mexican cession at the top of President Taylor's agenda.