Answer:
In 1845, Texas was annexed to the United States.
Explanation:
The Republic of Texas had declared its independence from the Republic of Mexico on March 2, 1836. At the time, most of the Texan population expressed a favorable attitude towards annexation by the United States. Both the leaderships of the two major American political parties, the Democrats and the Whig, opposed this process, since the introduction of a state with a strongly slave imprint could represent a further problem within the arena of heated discussions and pro- and anti-slavery debates within the Congress.
In addition, both wanted to avoid a war with Mexico, whose government had already expressed its willingness to recognize the sovereignty of its northern rebel province. From the 1840s, the economic fortune of Texas was in sharp decline, for this reason the President of the Republic of Texas, Sam Houston, had tried to start talks with the Mexican government to explore the possibility of obtaining independence, with the mediation of Great Britain.
In 1843 the Presidency of John Tyler, not aligning himself with the positions of any of the parties present at the Congress, decided to proceed in a completely autonomous and independent way to the annexation of Texas, with the aim of gaining the popular consent necessary to obtain a re-election to the Presidency. However, his official motivations were to oppose the supposed British policy of releasing slavery in Texas, which would have undermined the entire US slave system.
Through secret negotiations with Houston himself, President Tyler entered into an annexation treaty in 1844. When the documents of the agreement were submitted to the US Senate for ratification, the dictates for the terms of the annexation became public and the question of Texas annexation became a central topic of the election campaign during the presidential elections in the United States of America in 1844.