19. U.S. leaders begin to worry about Great Britain’s influence in Texas Some Americans oppose adding a slave state or fear war with Mexico Many Americans support manifest destiny, or westward expansion Polk’s victory shows strong American approval for Texas Annexation Texas have strong U.S. ties and badly need U.S. military and monetary aid 1844: 1844: 1844: 1845: 1845: Dec. 29, 1845: Cause Effect