美國 美國嚮西擴展  (1790年三月29日～1862年元月18日)

開端 終結 在位 1841年 1845年 

　　約翰·泰勒（1790年3月29日－1862年1月18日），美國第十任總統(1841年4月4日 – 1845年3月4日)，輝格黨人，是第一個因在任總統逝世而以副總統繼任為總統的人。因此，人們對首次對副總統繼任之後的地位感到睏惑。泰勒非常反感別人稱呼他為“副總統”或者“代總統”，並退回了所有對他稱呼非為“總統”信函。在他的堅持下，副總統得在繼任總統之後取得和總統一樣的地位。
　　
　　約翰·泰勒1841年就任副總統，一個月後繼任總統，迅速鞏固了手中的權力。在任期間，改組美國海軍；建立美國氣象局；結束了佛羅裏達州的第二次塞諾米爾戰爭。1861年初，主持華盛頓和平會議以調解南北方分歧。南北戰爭爆發後，他加入美國南方邦聯的議會，1862年逝世。
　　
　　1845年3月3日，就是泰勒卸任總統的前一天，美國國會按照兩院各三分之二多數議員的决議，推翻了泰勒此前對一項立法的否决。這是美國國會歷史上首次推翻總統否决。

　　John Tyler, Jr. (March 29, 1790 – January 18, 1862) was the tenth President of the United States (1841–1845) and the first ever to obtain that office via succession.
　　
　　A long-time Democratic-Republican, Tyler was nonetheless elected Vice President on the Whig ticket. Upon the death of President William Henry Harrison on April 4, 1841, only a month after his inauguration, the nation was briefly in a state of confusion regarding the process of succession. Ultimately the situation was settled with Tyler becoming President both in name and in fact. Tyler took the oath of office on April 6, 1841, setting a precedent that would govern future successions and eventually be codified in the Twenty-fifth Amendment. At 51 years old, he was the youngest U.S. president to take office to that point (whereas Harrison had been the oldest man to take office as president).
　　
　　Arguably the most famous and significant achievement of Tyler's administration was the annexation of the Republic of Texas in 1845. Tyler was the first president born after the adoption of the U.S. Constitution, the only president to have held the office of President pro tempore of the Senate, and the only former president elected to office in the government of the Confederacy during the Civil War (though he died before he assumed said office).