How did the position of the US Senate differ on the treaty of 1844 and the joint resolution of 1845?

The US Senate initially rejected the treaty of 1844, which aimed to annex Texas, due to concerns about slavery and the potential for conflict with Mexico. In contrast, the joint resolution of 1845, which sought to annex Texas through a simple majority vote in Congress, was passed more easily, reflecting a shift in public sentiment and political dynamics. The resolution's success was partly due to the growing desire for westward expansion and the belief in Manifest Destiny. Ultimately, the joint resolution circumvented the Senate's earlier rejection by using a different legislative approach.