After the death of President William Henry Harrison, Vice President John Tyler assumes the presidency. He is the first ever to do so, setting the precedent for presidential succession.

Tyler's entire cabinet, with the exception of Secretary of State Daniel Webster, resigns after Tyler vetoes a second bill for the establishment of a National Bank of the United States.

The Massachusetts Supreme Court establishes the legality of labor unions, including the right for workers to strike, in the case of Commonwealth v. Hunt.

The signing of the Webster-Ashburton Treaty normalizes U.S.-British relations by adjusting the Maine-Brunswick border, settling boundary issues around western Lake Superior, and resurveying numerous smaller borders.

In the congressional elections, the Democrats gain a majority over the Whigs in the House of Representatives, while at the same time defending their majority in the Senate.

The Texas Annexation Treaty is signed by the United States and the Republic of Texas.

The first telegraph line in the United States is completed between Washington, D.C., and Baltimore.

The Texas Annexation Treaty fails to gain the required two-thirds majority in the Senate amid controversy over the western expansion of the nation.

On June 26, 1844, President John Tyler married Julia Gardiner in a private ceremony at a New York City Episcopal church. It was the first time a President had wed while in office, and two days later the Tylers held a reception in the Blue Room of the White House to introduce the country to its new First Lady.

President Tyler's first wife, Letitia, died on September 10, 1842, becoming the first First Lady to die in the White House. She was already an invalid due to a stroke by the time she arrived in Washington, D. C., in 1841, and largely remained confined to the presidential mansion's second floor during her husband's term. Letitia Tyler made only one social appearance during her entire time in the capital. After her death, President Tyler and the nation mourned her passing.

But President Tyler's mourning ended just a few months later when he met Julia Gardiner in early 1843. Julia was the daughter of a prominent New York businessman, and she met the President while making the social rounds among Washington's political elite. Tyler found himself enraptured with the young lady and began to court her aggressively, proposing marriage early in their relationship. Julia at first declined, but eventually agreed.

Julia was thirty years younger than President Tyler, and the marriage instantly became the subject of intense gossip. Tyler's political opponents-Whigs and Democrats alike-seized upon the event as another opportunity to pummel the President. Yet the controversy did little to further damage Tyler's much-maligned reputation. He had already been passed over by the presidential nominating committees of both major parties the previous May, and the nation's political attention was fixed on the 1844 election between James K. Polk and Henry Clay. During the last eight months of his administration, Tyler and his new wife staged elaborate balls and receptions, while the public focused its attention on the 1844 presidential race.

James K. Polk is elected as the eleventh President of the United States on promises to “re-annex” Texas and “re-occupy” Oregon.

Congress passes the joint resolution (which only requires a simple majority by both houses) submitted by Tyler to annex Texas. The Republic of Texas votes to accept annexation on June 23.

On March 1, 1845, President John Tyler signed a joint resolution to annex Texas. The resolution called for Texas to enter the United States directly as a state, with its boundaries to be determined after annexation. Under the new resolution, the United States would not assume the Republic of Texas's sizable debt, but the new state would be allowed to keep its vast public lands (which could be used presumably to alleviate the debt). Texas could also consent to creating up to four more states out of the original area, with those above 30 degrees and 30 minutes created as free states, and those below the line formed as slave states.

President Tyler had long championed bringing Texas into the Union, and he interpreted Democrat James K. Polk's 1844 election victory as a popular mandate for territorial expansion and the annexation of Texas. After the Senate had rejected a treaty with Texas in June 1844, President Tyler decided to pursue annexation through a different means. Instead of ratifying a treaty, which required approval from two-thirds of the Senate, Tyler decided to use a joint resolution to annex Texas; a resolution only required a simple majority in the House and Senate for approval.

President Tyler concentrated his annual message in December almost entirely on the issue of Texas, and he quickly submitted to Congress a joint resolution to admit Texas into the Union. The House passed a compromise resolution in January 1845 but efforts in the Senate moved slowly until Polk arrived in Washington, D.C., in mid-February. The President-elect immediately began to exert pressure on the Senate, hinting that patronage appointments might hinge on the bill's passage, and the Senate finally passed an amended version of the bill. The revised bill approved the terms of the House version with the added stipulation that the President was to decide whether to annex Texas immediately or settle another annexation treaty with the Republic. The measure passed the Senate 27 to 25.

Although Tyler signed the resolution on March 1, 1845, the presidential choice between immediate annexation and a new treaty was intended for Polk. Secretary of State John C. Calhoun, however, pushed Tyler to offer Texas annexation immediately, arguing that there was no reason for delay. Tyler, already eager for some credit in the annexation of Texas and wanting it as the crowning achievement of his administration, took little convincing. President Tyler officially dispatched word to Texas, offering immediate annexation if Texas approved, on his last full day in office, March 3, 1845. Texas joined the United States as the twenty-eighth state on December 29, 1845.

Florida is admitted as a slave state, making it the twenty-seventh state in the Union.

James K. Polk is inaugurated as the eleventh President of the United States.