Editing 1803 (section)

=== October–December ===
* [[October 14]] – [[Odisha|Orissa]], an area of [[India]] along the [[Bay of Bengal]] that comprises the modern-day Indian state of [[Odisha]], is occupied by the British under the [[British East India Company]], after the Second Anglo-Maratha War.<ref>Chandan Kumar Sadangi and Sanjay Mohapatra, ''Change Management for Organizations: Lessons from Political Upheaval in India'' (Emerald Group Publishing, 2017) p x</ref>  The [[Maratha Empire]] formally cedes the area in the Treaty of [[Deogaon]], signed on December 17.<ref>Lieutenant-Colonel H. F. Murland, ''Baillie-Ki-Paltan: Being a History of the 2nd Battalion, Madras Pioneers 1759–1930'' (Andrews UK Ltd., 2012) p122</ref>
* [[October 20]] – The Senate ratifies the [[Louisiana Purchase]] Treaty, doubling the size of the United States.
* [[November 18]] – [[Haitian Revolution]]: [[Battle of Vertières]] – The Haitian army, led by [[Jean-Jacques Dessalines]], defeats the French army sent by [[Napoleon]].
* [[November 30]]
** The [[Balmis Expedition]] starts in Spain, with the aim of vaccinating millions against smallpox in [[Spanish America]] and the [[Philippines]].
** At [[the Cabildo]] in [[New Orleans]], Spanish representatives Governor Manuel de Salcedo and the Marqués de Casa Calvo officially transfer [[Louisiana (New Spain)]] to French representative Prefect [[Pierre Clément de Laussat]].<ref>Robert S. Levine, ''Dislocating Race and Nation: Episodes in Nineteenth-Century American Literary Nationalism'' (University of North Carolina Press, 2009) p27</ref> Barely three weeks later, France transfers the same land to the United States.
* [[December 9]] – The proposed [[Twelfth Amendment to the United States Constitution]], requiring that electoral ballots distinctly list the choice for president and the choice for vice president, is approved by Congress for submission to the states for ratification; passed in the wake of the problems in the [[1800 United States presidential election|1800 presidential election]], the amendment is ratified by 13 of the 17 states and is proclaimed in effect on September 25, 1804.<ref>''The Constitution of the United States of America, As Amended'', ed. by Jack Brooks (U. S. House of Representatives, 1992) pp15-16</ref>
* [[December 20]] – The [[Louisiana Purchase]] is completed as the French prefect, de Laussat, formally transfers ownership of land between the Mississippi River and the Rocky Mountains to the United States, by way of commissioners [[William C. C. Claiborne]] and [[James Wilkinson]].<ref>Charles Etienne and Arthur Gayarré, ''History of Louisiana: The American Domination'' (Pelican Publishing, 1972)</ref>  Claiborne is appointed as the area's first American governor.<ref>C. A. Goodrich, ''History of the United States'' (Huntington and Hopkins, 1823) p306</ref>