Who was known for his role in advocating for Texas annexation to the United States?

The correct answer is John Tyler. He played a significant role in advocating for the annexation of Texas into the United States. Tyler, who was the President of the United States from 1841 to 1845, actively pursued the annexation as part of his administration's foreign policy. His commitment to this cause was evident in his efforts to push through congressional resolutions supporting Texas' admission into the Union, which ultimately paved the way for the tense and politically charged process of annexation.

Tyler's motivation for annexation was driven by several factors, including the desire to expand American territory, the idea of Manifest Destiny, and the political benefits of garnering support from Southern states who favored the expansion of slave territory. The efforts that were led by Tyler culminated in the joint resolution passed by Congress in 1845 that formally invited Texas to join the United States.

While other figures such as Sam Houston were crucial in the context of Texas history and the independence of Texas from Mexico, it was John Tyler's direct actions and political maneuvers that were pivotal in the eventual annexation of Texas.