After Texas gained independence, the United States of America acknowledge its reign. Sam Houston and Stephen later on became the president and the State Secretary respectively. At the same time, Texas was battling with the issue of being annexed to the United States of America. Based on the fact that America had a tendency to gather up land all over, the result seemed foreordained to a certain extent. However, there were fears of war with Mexico and therefore, Presidents, Van Buren, Jackson and Tyler knew about the issue. Slavery in Texas was also another issue. All the same, Texas pursued her annexation by threatening to join France or Great Britain if the United States was not ready to accept the approach by Texas. Due to frustrations, Sam Houston wrote to Jackson about the annexation of Texas to the United States of America. However, ten more years elapsed and was later annexed to the union in 1845.
Northern Mexico became part of the United States through the Mexican-American war. This war was thought to have been occasioned by the annexation of Texas into the United States of America. This is because Mexico considered Texas a part of its territory. However, the 1836 revolution in Texas saw stand out alone and thus was easily annexed to the United States. The U.S-Mexican war then arose. This was known as the first American Intervention; an armed conflict which took place between Mexico and the United States in 1846 to 1848. It was a heated fight where the forces of America invaded, the republic of California, New Mexico and other parts of northern Mexico. At the same time, the American Navy forces carried out a blockade and controlled a number of garrisons on the Alta California Pacific coast. Other American forces captured Mexico City which left Mexico with no choice other than to succumb to the pressure and leave the northern Mexico to the United States. Therefore, Texas annexation was a peaceful treaty while the annexation of northern Mexico was through war.