I have a book where 20 historians each related an event that changed U.S. history. One that definitely concerns the West was the presidential election of 1844. If anyone has ever thought that it does not really matter who is elected president, perhaps the results of the election of 1844 should change his/her mind.
Leading candidates in the spring of 1844 were Henry Clay, a Whig, and Martin Van Buren, a Democrat. There was no Republican Party yet. Van Buren previously had served as president from 1837 to 1841 and wanted to be back in office after four years out.