テキサス併合
With the Webster-Ashburton Treaty ratified in 1843, Tyler was ready to make the annexation of Texas his "top priority". Representative Thomas W. Gilmer of Virginia was authorized by the administration to make the case for annexation to the American electorate. In a widely circulated open letter, understood as an announcement of the executive branch's designs for Texas, Gilmer described Texas as a panacea for North-South conflict and an economic boon to all commercial interests. The slavery issue, however divisive, would be left for the states to decide as per the US Constitution. Domestic tranquility and national security, Tyler argued, would result from an annexed Texas; a Texas left outside American jurisdiction would imperil the Union. Tyler adroitly arranged the resignation of his anti-annexation Secretary of State Daniel Webster, and on June 23, 1843 appointed Abel P. Upshur, a Virginia states' rights champion and ardent proponent of Texas annexation. This cabinet shift signaled Tyler's intent to pursue Texas annexation aggressively.