Year by year · 19th century

1803

1803 in world history: 19 events, 13 births, 13 deaths, 7 states founded and 20 that came to an end. 1,203 recorded states existed that year.

Events

24 February
Marbury v. Madison establishes judicial review
Chief Justice John Marshall ruled that the Supreme Court could strike down acts of Congress that conflicted with the Constitution. The decision became a cornerstone of American constitutional law.
30 April
Louisiana Purchase treaty doubles the size of the United States
American envoys in Paris agreed to buy France's Louisiana territory for $15 million. The deal, dated this day, gave the young republic the vast basin west of the Mississippi.
United States Louisiana Paris
25 May
Ralph Waldo Emerson is born in Boston
Emerson became the leading voice of Transcendentalism. Essays such as 'Self-Reliance' shaped American thought and influenced Thoreau and Whitman.
Boston
20 October
The US Senate ratifies the Louisiana Purchase
The Senate approved the treaty buying Louisiana from France by 24 votes to 7. For 15 million dollars, the United States gained some 828,000 square miles, roughly doubling its territory.
United States Louisiana
20 December
The United States takes possession of Louisiana
In a ceremony in New Orleans, France formally handed the Louisiana Territory to the United States. The purchase roughly doubled the country's size and gave it control of the Mississippi.
United States Louisiana
Event
Reichsdeputationshauptschluss
The Reichsdeputationshauptschluss, or Imperial Recess, was the final resolution of an imperial deputation adopted at Regensburg in 1803.
Event
Act of Mediation
The Act of Mediation was the constitution imposed on Switzerland by Napoleon Bonaparte in 1803, replacing the unstable Helvetic Republic after civil strife in 1802.
Battle
Battle of Assaye
The Battle of Assaye was fought in 1803 in western India during the Second Anglo-Maratha War.
Battle
Battle of Argaon
The Battle of Argaon was fought on 29 November 1803 in the Deccan between a British force under Arthur Wellesley, later Duke of Wellington, and the armies of Raghuji II Bhonsle of Nagpur and Daulat Rao Scindia.
Battle
Battle of Vertières
The Battle of Vertières was fought on 18 November 1803 outside Cap-Français, when the Haitian revolutionary army under Jean-Jacques Dessalines, with François Capois prominent in the assault, defeated the French forces of General Rochambeau.
Event
Dance of Zalongo
The Dance of Zalongo is the name given to the mass suicide of Souliote women on Mount Zalongo in Epirus in December 1803, after Ali Pasha of Ioannina had forced Souli to surrender.
Treaty · Peace
Treaty of Deogaon
The Treaty of Deogaon was signed on 17 December 1803 between the British East India Company and Raghuji II Bhonsle of Nagpur after his defeats at Assaye and Argaon in the Second Anglo-Maratha War.
Event
Treaty of Malmö (1803)
The Treaty of Malmö of 1803 was an agreement by which Sweden pawned the city of Wismar, with the island of Poel and the district of Neukloster, to the Duke of Mecklenburg-Schwerin for 1,250,000 riksdaler for 100 years.

ProfileState1021 states with a known seat in 1803Open the atlas at 1803 →

In the profiles

United StatesThe Louisiana Purchase roughly doubles the country’s area
Electoral PalatinateThe Imperial Recess divides the remaining lands among Baden and others
Swiss ConfederationNapoleon's Act of Mediation creates a confederation of nineteen cantons

Wars and longer events

Born in 1803 13

Died in 1803 13

States founded 7

States that came to an end 20

All years → The 19th century →

Cite this page

APA: The Epoch Institute. (2026). 1803. In The Epoch Institute, Year by Year. https://the-epoch-institute.org/years/1803
MLA: “1803.” The Epoch Institute, Year by Year, The Epoch Institute, 2026, https://the-epoch-institute.org/years/1803. Accessed .
Chicago: The Epoch Institute. “1803.” The Epoch Institute, Year by Year. 2026. https://the-epoch-institute.org/years/1803.
Harvard: The Epoch Institute (2026) ‘1803’, The Epoch Institute, Year by Year. Available at: https://the-epoch-institute.org/years/1803 (Accessed: ).