|Boundaries of Texas as annexed, 1845|
Anglo immigrants, mainly from the southern United States, began to migrate to Mexican Texas in the early 1820s at the request of the Mexican government, which sought to increase the sparsely populated land of its northern border.
The boundaries of the United States and neighboring nations as they appeared in 1843
The Anglo Americans soon became the majority in Texas and eventually became disillusioned with the Mexican authorities.
The state of Coahuila, which was part of Texas since 1824, approved a plan for the gradual emancipation of slaves in the state in 1827, angering many of the new settlers who had moved to Texas from USA and had lived in Mexico for about a decade.
|James K. Polk of Tennessee, president-elect of the United States during the joint house Texas treaty debates.|
For these and other reasons, (Manifest Destiny) Texas declared its independence from Mexico, which is at war with Mexico. In 1836, the fighting ended and Sam Houston became the first president of the Republic of Texas, elected on a platform favoring annexation to the United States.
A map, published in the Newark Daily Advertiser as the U.S. Senate was considering a Joint Resolution for the Annexation of Texas that had been adopted by the House of Representatives.
The citizens of Texas approved the new constitution and the annexation ordinance on October 13, 1845. US President James K. Polk signed the documents formally integrating Texas in United States on December 29, 1845.