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20 Star Flag 

  • Flown from April 4, 1818 – July 13, 1819

  • US President: James Monroe (1817-1825)

The Twenty Star Flag became official due to the Flag Act of 1818 by the 3rd Congress. It returned the stripes to 13 and specified 5 more stars were to be added. The five stars added were for the admission of Tennessee (June 1st, 1796), Ohio (March 1st, 1803), Louisiana (April 30th, 1812), Indiana (December 11th, 1816), and Mississippi (December 10, 1817). The 20th Star Flag was official for one year.

Politics and Government


April 13, 1818: The United States Congress adopts the flag of the United States with 13 red and white stripes and 20 stars.


October 20, 1818: The United States and the United Kingdom establish the boundary between Canada and the U.S. along the 49th parallel.


December 3, 1818: Illinois becomes the 21st state to join the Union.


President James Monroe declares the Missouri Territory's southern boundary as the 36°30' parallel, influencing the debate on slavery expansion (1818).


The McCulloch v. Maryland Supreme Court case establishes the principle of implied powers in relation to the U.S. Constitution (1819).


March 6, 1820: The Missouri Compromise is enacted, admitting Missouri as a slave state and Maine as a free state.


Science, Technology and Medicine



September 23, 1818: A patent is granted for the first successful typewriter, invented by William Austin Burt.


May 17, 1819: The first surgical operation using ether as an anesthetic is performed in Georgia.


September 10, 1819: The steamship "Savannah" becomes the first steamship to cross the Atlantic Ocean





July 10, 1819: Author and abolitionist William Ellery Channing delivers a sermon on Unitarian Christianity.



Arts, Culture and Literature


The Savannah Theatre in Georgia, the oldest continually operating theater in the United States, opens (1818).


June 3, 1818: American abolitionist and women's rights activist Harriet Martineau is born.




The first documented bicycle ride in the United States takes place in New York City (1819)




International Events (April 4, 1818 - July 3, 1819)



Mary Shelley's "Frankenstein; or, The Modern Prometheus" is published, becoming a seminal work in science fiction (1818).


December 5, 1815: Author Jane Austen's novel "Emma" is published.


The Congress of Aix-la-Chapelle aims to restore European stability after the defeat of Napoleon (1818).

Major Armed Conflicts


First Seminole War


  • 24 May 1818 – General Andrew Jackson captures Pensacola, FL


International Armed Conflicts:


03 June 1818 – Maratha Wars end in India between Great Britain and Maratha Confederacy


National Historical Events


04 April 1818 – The Third United States Congress enacts the Flag Act of 1818, which reinstated the rule of 13 horizontal stripes, and the number of stars shall match the number of States. The law provided that changes made to the star count would become effective the following July 4th after States were admitted to the Union.


·      The text of the Flag Act of 1818: An Act to establish the flag of the United States.  Be it enacted by the Senate and House of Representatives of the United States of America, in Congress Assembled, That from and after the fourth day of July next, the flag of the United States be thirteen horizontal stripes, alternate red and white: that the union be twenty stars, white in a blue field.  

And be it further enacted, that on the admission of every new state into the Union, one star be added to the union of the flag; and that such addition shall take effect of the fourth day of July then next succeeding such admission.

16 April 1818 – the US Senate ratified the Rush-Bagot Treaty. This treaty demilitarized the US/Canada border and naval fleet disarmament from the Great Lakes occurs on April 28th per President Monroe.


22 February 1819 – The Adams-Onis Treaty is signed between the United States and Spain. This treaty ceded control of Florida to the US.


21 May 1819 – First bicycles, called velocipedes or “swift walkers”, introduced in the United States are used in New York City. 


20 October 1818 – the 49th parallel forms the US Canadian border. The United States and Great Britain agree to joint control of the Oregon Territory

International Historical Events

25 December 1818 – The first known Christmas carol, Silent Night, Holy Night, is sung in Austria

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