Manifest Destiny was a popular belief during the 19th century that settlers in the United States were fated to spread across North America.
In 1843, United States President John Tyler pursued the annexation of Texas independently by gaining popular support for the next election. He was able to secure the treaty of the annexation in 1844. It came under public scrutiny when it was passed on to the Senate for ratification. The Senate rejected the Tyler-Texas Treaty.
Meanwhile, Pro-Texas-annexation southern Democratic delegates secured pro-Texas Manifest Destiny James K. Polk’s nomination. He won against anti-annexation Whig Henry Clay in the 1844 Presidential election.
President John Tyler compelled the Congress to pass the treaty and the House of Representatives, with its Democrat majority, complied.
The Senate approved a compromised version of the House bill.
In 1845, President John Tyler signed the bill and offered its immediate annexation. James K. Polk supported it and a ratified agreement was accepted by popular consent.
Texas was officially signed as the 28th state of the Union In December 29, 1845.