The presidency of John Tyler began on April 4, 1841, when John Tyler became president of the United States upon the death of President William Henry Harrison, and ended on March 4, 1845, upon the completion of Harrison's term.

1841 April 1841 April 4 Vice President John Tyler becomes the tenth president of the United States following the death of President William Henry Harrison. This is the first time the vice president has filled a vacancy in the presidency. Tyler retains Harrison's cabinet, with Daniel Webster as secretary of state, Thomas Ewing as secretary of the treasury, John Bell as secretary of war, John J. Crittenden as attorney general, Francis Granger as postmaster general, and George Edmund Badger as secretary of the navy. April 6 – Tyler is inaugurated as the tenth president of the United States. April 9 – Tyler gives an address outlining his intentions as president. He advocates direct appropriations that cannot be subject to interpretation by bureaucrats and criticizes government debt in peacetime.

May 1841 May 31 – The 27th United States Congress convenes for its first session.

June 1841 June 1 – Tyler addresses a special session of Congress that had been convened by Harrison. He advocates westward expansion of the United States and requests restrictions on state banks. June 30 Tyler delivers a special message to the House of Representatives on behalf of New York requesting that Congress pass a bankruptcy law. A law is passed granting Julia Gardiner Tyler, the widow of President Harrison, a pension of $25,000 ().

July 1841 July 15 – Tyler nominates Peleg Sprague to the District Court for the District of Massachusetts. He nominates Abner Nash Ogden to the District Courts for the District of Eastern Louisiana and the District of Western Louisiana, but Ogden declines. July 21 – A law is passed authorizing the federal government to borrow up to $12 million.

August 1841 August 13 – The Independent Treasury Act of 1840 is repealed, mandating that funds be removed from the act's depositories. August 16 Tyler vetoes a bill that would "incorporate the subscribers to the Fiscal Bank of the United States". He believes that the federal government does not have this power under the Constitution. The frigate USS Congress is launched at the Portsmouth Naval Shipyard. August 19 – The Bankruptcy Act of 1841 is passed, establishing uniform bankruptcy laws for the nation.

September 1841 September 1 – Tyler nominates Theodore Howard McCaleb to the District Courts for the District of Eastern Louisiana and the District of Western Louisiana. September 4 – The Preemption Act of 1841 is passed. It authorizes the sale of public land for $1.25 per acre to fund internal improvements. September 9 – Tyler vetoes a law that would have effectively restored the Bank of the United States. September 11 – Tyler's cabinet resigns in protest of Tyler's veto two days previously, with the exception of Secretary of State Daniel Webster. September 13 Walter Forward succeeds Thomas Ewing as secretary of the treasury, Hugh S. Legaré succeeds John J. Crittenden as attorney general, Charles A. Wickliffe succeeds Francis Granger as postmaster general, and Abel P. Upshur succeeds George E. Badger as secretary of the navy. Congress passes a resolution written by members of the Whig Party, condemning Tyler and disavowing him from the party. The 27th United States Congress adjourns from its first session. September 25 – Tyler issues a proclamation stating that American citizens who commit crimes in Canada will be prosecuted.

October 1841 October 12 – John Canfield Spencer succeeds John Bell as secretary of war.

November 1841

December 1841 December 6 – The 27th United States Congress convenes for its second session. December 7 – Tyler delivers the 1841 State of the Union Address. December 22 – The frigate USS Mississippi is commissioned for the United States Navy prior to its launching at the Philadelphia Navy Yard in early 1842.

1842 January 1842 January – The Supreme Court issues its decision in Prigg v. Pennsylvania. It rules that state law cannot interfere with federal laws regarding the capture of slaves who escaped across state lines. January 17 – Tyler delivers a special message to the Senate declaring the resolution of a boundary dispute between the Republic of Texas and the United States. January 18 – Tyler nominates Horace Binney to the District Court for the Eastern District of Pennsylvania, but Binney declines. January 25 – The Supreme Court issues its decision in Swift v. Tyson. It rules that federal courts can interpret state law through "general commercial law" instead of being bound to interpretations by the state courts.

February 1842 February 5 – Tyler nominates Thomas Bradford to the District Court for the Eastern District of Pennsylvania, but the Senate rejects his nomination. February 9 – A resolution is passed to form a committee to investigate the New York Custom House.

March 1842 March – The Massachusetts Supreme Judicial Court issues its decision in Commonwealth v. Hunt. It rules that trade unions cannot be prosecuted as criminal conspiracies and their right to strike is legally protected in Massachusetts. March 1 – The Supreme Court issues its decision in Prigg v. Pennsylvania. It rules that per the Supremacy Clause states cannot interfere with the Fugitive Slave Act of 1793 but do not have to assist in its enforcement. This allows for a significant expansion of the Underground Railroad. March 3 – Tyler nominates Archibald Randall to the District Court for the Eastern District of Pennsylvania. March 4 – The Supreme Court issues its decision in Dobbins v. Erie County. It rules that states cannot tax federal offices. March 8 – Tyler requests that Congress pass legislation that gave the federal government supremacy over the states in regard to deportation law. March 12 – Tyler criticizes the Senate for rejecting his nominee for survey-general of Illinois Territory and Missouri Territory, and he renominates. March 17 – The United States signs a treaty with the Wyandot people. March 23 – Tyler tells Congress that he cannot comply with a resolution that would allow the House of Representatives control over presidential appointments. March 25 – Tyler asks Congress to address the government debt.

April 1842 April 4 – Tyler nominates Charles Dewey to the District Court for the District of Indiana, but Dewey declines. April 7 – Tyler submits a report to Congress on the boundary dispute between the United States and British Canada. April 8 – Tyler nominates Samuel Prentiss to the District Court for the District of Vermont. April 16 – The brigs USS Somers and USS Truxtun are launched at the New York Navy Yard and the Gosport Navy Yard, respectively. April 26 Tyler nominates Elisha Mills Huntington to the District Court for the District of Indiana. The brig USS Bainbridge is launched at the Boston Navy Yard.

May 1842 May 5 – The frigate USS Savannah is launched at the New York Navy Yard. May 10 – Tyler condemns Florida for engaging in conflict with Indian forces. He asks Congress to offer land grants for families who move to Florida. May 16 – Tyler authorizes Congress to issue brevets for veterans who served in Florida. May 20 – The United States signs the Third Treaty of Buffalo Creek with the Seneca people. May 24 – The USS Cumberland is launched at the Boston Navy Yard.

June 1842 June 25 – The Apportionment Act of 1842 ties House elections to individual districtss instead of state-wide elections. Tyler criticizes the law as potentially unconstitutional.

July 1842 July 22 – Representative John Botts formally proposes that Tyler be impeached. July 26 – The sloop-of-war USS Saratoga is launched at the Portsmouth Navy Yard.

August 1842 August 9 The United States signs the Webster–Ashburton Treaty with the United Kingdom. It resolves a border dispute between Maine and the British colony of New Brunswick, allowing the two countries to normalize relations. Tyler vetoes a tariff because it is above 20 percent and does not sufficiently restrict the distribution of land sale proceeds. A select committee led by Representative John Quincy Adams is formed in response. August 11 – Tyler submits documents on the border dispute with British Canada on Congress. August 16 – The House Select Committee formed in response to Tyler's veto determines that Tyler is abusing his power to veto legislation. It recommends amending the constitution to reduce the president's veto power. August 17 – The House votes on proposing an amendment to the Constitution to make it easier to override a presidential veto. The vote is 98 in favor and 90 opposed, which fails to meet the required supermajority. August 26 – A law is passed defining the start of the fiscal year as July 1. August 29 – A law is passed authorizing Supreme Court and district court judges to issue writs of habeas corpus. August 30 Tyler signs the Tariff Act of 1842 despite his opposition to a tariff above 20 percent. It reverts American tariffs to their state in 1832. Distribution of lands under the Preemption Act of 1841 is halted. Tyler condemns the House Select Committee's accusation that he was abusing his power and accuses the House of violating the Constitution by criticizing him without offering him a chance to respond. The House rejects Tyler's message and does not enter it into record. August 31 – The 27th United States Congress adjourns from its second session.

September 1842 September 10 – Tyler's wife, Letitia Christian Tyler, dies.

October 1842 October 4 – The United States signs the Treaty of La Pointe with the Chippewa. October 11 – The United States signs a treaty with the Sauk people and Fox people.

November 1842 November – The Democratic Party takes control of the House of Representatives from the Whig Party in the 1842 House of Representatives elections while maintaining control of the Senate.

December 1842 December 5 – The 27th United States Congress convenes for its third session. December 6 – Tyler delivers the 1842 State of the Union Address. December 30 – Tyler asks Congress to establish relations with China and with the Hawaiian Kingdom. He discourages the colonization of islands in the Pacific.

1843 January 1843 January 10 – The House of Representatives votes against a proposal to impeach Tyler.

February 1843 February 18 – Tyler announces the dismissal of Captain Thomas ap Catesby Jones for his Capture of Monterey against Mexico. February 20 – The Supreme Court issues its decision in Louisville Railroad Co. v. Letson. It rules that corporations are under the jurisdiction of the state that chartered it. This overturns Bank of the United States v. Deveaux. February 23 – The Supreme Court issues its decision in Bronson v. Kinzie. It rules that states cannot pass laws that retroactively change financial agreements because this violates the Contract Clause of the Constitution.

March 1843 March 3 Congress allocates $30,000 to initiate a project led by Samuel Morse to build telegraph lines in the United States. The Bankruptcy Act of 1841 is repealed. Secretary of War John Canfield Spencer succeeds Walter Forward as secretary of the treasury. The 27th United States Congress adjourns from its third session. March 8 – James Madison Porter succeeds John Canfield Spencer as secretary of war.

April 1843

May 1843 May 8 – Daniel Webster resigns as secretary of state. May 22 – Migration across the Oregon Trail begins when over one hundred wagons depart from Independence, Missouri.

June 1843 June 13 – The frigate USS Raritan is launched at the Philadelphia Navy Yard. June 17 – The Bunker Hill Monument is dedicated in Boston with Tyler in attendance. June 20 – Attorney General Hugh S. Legare dies.

July 1843