Americas apetite for expansion was most clearly at work in Texas. The Spanish had been less successful in colonizing Arizona and Texas than in New Mexico and Florida. In some regions the Spanish monarchy awarded huge land grants to a few ex-soldiers and colonists, who turned the grants into profitable cattle ranches. This showed to work in California, but it was not the case in Texas. By 1830 the total population in Texas was about 20,000: the area was huge and nearly unsettled. Half of the state was still not settled at the end of the Civil War.
In eastern Texas during the first half of the eighteenth century, French traders from Louisiana undermined the authority and influence of the Spanish missions. The French furnished the Indians with guns, ammunition, and promises of protection. By 1750 some Indian tribes were using Spanish horses and French rifles to raid Spanish settlements in Texas. The plundering helps to explain why Texas was one of the most sparsely populated provinces on the northern frontier of New Spain. In 1790 the total population in Texas was 2,510, while in New Mexico it exceeded 20,000. At the same time, Indians thwarted efforts to establish catholic missions. In contrast to Texas, 40 percent of Californiaís Indian population had embraced Catholicism by 1803.
In many ways the settlers faced a new culture. Areas were already occupied by Indians and Mexicans, who had lived in the region for centuries and had established their own distinctive customs and ways of life. During the expansion they were joined by Americans of diverse ethnic origin and religious persuasion. Many Americans were as contemptuous of the Mexicans as they were of Indians, and viewed Mexicans as ignorant, indolent and conniving. The vast majority of the Spanish-speaking people resided in New Mexico. Most of these were of mixed Indian and Spanish blood and were usually poor ranch hands or small farmers and herders.
In the 1820`s settlers from Tennessee, Kentucky, Arkansas and Missouri moved to Texas. These were mostly yeoman farmers driven by the Mexican governments policy instituted to attract settlers. Americans were welcomed into the region as stabilizing the border, but the result was a Texas rapidly turning into an American province. The total population on the eve of the Texas revolution, in 1835, was about 35,000 people. During the 19th century there were streams of migration into Texas. Between 1821 and 1836 an estimated 38,000 settlers, on promise of 4,000 acres (1,620 hectares) per family for small fees, trekked from the United States into the territory.
Immigration was probably tarded because the official opposition of the Mexican government to Negro slavery. Though antislavery policy was never rigorously enforced, any southern who brought Negroes to the state ran the risk of forfeiting them. Anyway, the opposition was one of the major facts that tarded lower southern immigration, and the issue of slavery that characterized American politics in the first part of the nineteenth century.
In eastern Texas 20,000 settlers and 1,000 slaves outnumbered the 5,000 Mexicans in the area by 1830. The settlers showed little interest in Catholicism and other aspects of Mexican culture. The expansion was a quest for a better chance and more living room and in many ways the Americans kept their culture. Economic opportunities marked mainly the settlers, not cultural preferences This was perhaps one of the reasons why Texas later became choose American annexation.
Later the immigration was stopped. The Mexican government grew alarmed at the immigration threatening to engulf the province. Military troops were moved to the border to enforce the policy. Still there was illegal immigration. Immigrants crossed the border easily and by 1835 there were ten times as many Americans (30,000) as Mexicans. The settlers demanded greater representation and more power from the Mexican Government. Revolts broke out in 1832 and 1833. Instead, General Santa Anna, dissolved the national congress late in 1834, and became dictator in Mexico.
In Texas, American settlers decided to promote their own independence from Mexico. Suddenly, it seemed, that Southwest was a ripe new frontier for American exploitation and settlement. This can be explained by Americans and their concept of Manifest Destiny. Manifest Destiny was a moral justification for American expansion, or at itís worst, a cluster of flimsy rationalizations for naked greed and imperial ambition. Manifest Destiny must be seen in context with the increase of the American population. By 1840 the total population in America had doubled since about 1800 and the pattern of population forced them to search new land.