1798

January–June

• January - Eli Whitney contracts with the U.S. federal government for 10,000 muskets, which he produces with interchangeable parts.
• January 4 - Constantine Hangerli enters Bucharest, as Prince of Wallachia.
• January 22 - A coup d'état is staged in the Netherlands. Unitarian Democrat Pieter Vreede ends the power of the parliament.
• February 10 - The Pope is taken captive, and the Papacy is removed from power, by French General Louis-Alexandre Berthier.
• February 15 - U.S. Representative Roger Griswold beats Congressman Matthew Lyon with a cane, after the House declines to censure Lyon for earlier spitting in Griswold's face; the House declines to discipline either man.
• March - the Irish Rebellion of 1798 begins when the Irish Militia arrest the leadership of the Society of United Irishmen, a group unique amongst Irish republican and nationalist movements in that it unifies Catholics and Protestants around republican ideals. This month, Lord Castlereagh is appointed Acting Chief Secretary for Ireland and on March 30 martial law is proclaimed here. The first battles in the rebellion are fought on May 24 and it continues through September, but the rebels receive much less than the expected support from France, which sends only 1,100 men.
• March 5 - French troops enter Bern.
• March 7 - French forces invade the Papal States and establish the Roman Republic.
• April 7 - The Mississippi Territory is organized by the United States, from territory ceded by Georgia and South Carolina; later it is twice expanded, to include disputed territory claimed by both the U.S. and Spain.
• April 12 - The Helvetic Republic, a French client republic, is proclaimed following the collapse of the Old Swiss Confederacy after the French invasion; Aarau becomes the republic's temporary capital.
• April 26 - France annexes Geneva.
• April 30 - The United States Department of the Navy is established as a cabinet-level department. Benjamin Stoddert, a civilian businessman, is appointed as the first Navy Secretary by President Adams.
• May 7 - French Revolutionary Wars: A French force attempting to dislodge a small British garrison on the Îles Saint-Marcouf is repulsed with heavy losses.
• May 9 - Napoleon sets off for Toulon, sailing aboard Vice-Admiral Brueys's flagship L'Orient; his squadron is part of a larger fleet of over 300 vessels, carrying almost 37,000 troops.
• May 27 - Pitt–Tierney duel takes place on Putney Heath. British Prime Minister William Pitt the Younger fights a duel against opposition politician George Tierney
• June 12
• * The French take Malta.
• * A moderate coup d'état in the Netherlands deposes Pieter Vreede.
• June 13 - Mission San Luis Rey de Francia is founded in California.
• June 18 - The first of the four Alien and Sedition Acts, the Naturalization Act of 1798, is signed into law by U.S. President Adams, requiring immigrants to wait 14 years rather than five years to become naturalized citizens of the United States. On June 25, another law is signed authorizing the imprisonment and deportation of any non-citizens deemed to be dangerous.

  July–December

• July 1 - Egyptian Campaign: Napoleon disembarks his French army in Marabout Bay.
• July 7
• * Quasi-War: The United States Congress rescinds treaties with France, sparking the war.
• * In the action of USS Delaware vs La Croyable, the newly-formed United States Navy makes its first capture.
• July 11 - The United States Marine Corps is re-established under its present name.
• July 12 - Battle of Shubra Khit: French troops defeat the Mamelukes, during Napoleon's march from Alexandria to take Cairo.
• July 14 - The fourth of the Alien and Sedition Acts, the Sedition Act of 1798 is signed into law, making it a federal crime to write, publish, or utter false or malicious statements about the United States government.
• July 16 - The Relief of Sick and Disabled Seamen Act is signed into law, creating the Marine Hospital Service, the forerunner to the current United States Public Health Service Commissioned Corps.
• July 21 - Battle of the Pyramids: Napoleon defeats Ottoman forces near the Pyramids.
• July 24 - Napoleon occupies Cairo.
• July 31 - A second round of elections are held in the Netherlands ; no general elections this time.
• August 1 - Battle of the Nile : Lord Nelson defeats the French navy under Admiral Brueys. 11 of the 13 French battleships are captured or destroyed, including the flagship Orient whose magazine explodes; Nelson himself is wounded in the head.
• August 22 - French troops land at Kilcummin in County Mayo to assist the Irish Rebellion.
• September - Charles Brockden Brown publishes the first significant American novel, the Gothic fiction Wieland: or, The Transformation; an American Tale.
• September 5 - Conscription is made mandatory in France by the Jourdan Law.
• September 10
• * The Piedmontese Republic is declared in the territory of Piedmont.
• * Battle of St. George's Caye: Off the coast of British Honduras, a group of European settlers and Africans defeat a Spanish force sent from Mexico to drive them out.
• September 18 - Lyrical Ballads is published anonymously by Samuel Taylor Coleridge and William Wordsworth, inaugurating the English Romantic movement in literature.
• September 23 - Battle of Killala: in the last land battle of the Irish Rebellion of 1798, British troops defeat the remaining rebel Irish and French forces at Killala.
• October 2 - The Cherokee nation signs a treaty with the United States allowing free passage through Cherokee lands in Tennessee through the Cumberland Gap through the Appalachian Mountains from Virginia into Kentucky.
• October 7 - U.S. Representative Matthew Lyon of Vermont becomes the first member of Congress to be put on trial for violating the new Sedition Act of 1798.
• October 12
• * Battle of Tory Island: A British Royal Navy squadron, under Sir John Borlase Warren, prevents French Republican ships, commanded by Jean-Baptiste-François Bompart, from landing reinforcements for the Society of United Irishmen on the County Donegal coast; Irish leader Wolfe Tone is captured and later dies of his wounds. This ends the Irish Rebellion of 1798.
• * Peasants War against the French occupiers of the Southern Netherlands begins in Overmere.
• October 22 - Capitulation of the French garrison at Hyderabad to East India Company troops under James Kirkpatrick, British Resident.
• October 23 - The Ottoman–Albanian forces of Ali Pasha of Janina defeat the French and capture the town of Preveza in the Battle of Nicopolis.
• October 25 - The Ottoman–Albanian forces of Ali Pasha of Janina capture Butrint from the French after a week-long siege.
• November 4 - The Russo-Ottoman siege of Corfu, held by the French, begins.
• November 8 - British whaler John Fearn becomes the first European to land on Nauru.
• November 28 - Trade between the United States and modern-day Uruguay begins when John Leamy's frigate John arrives in Montevideo.
• December 5 - Peasants War in the Southern Netherlands: The revolt is crushed in Hasselt; during the uprising it is estimated that 5,000 to 10,000 people have been killed.
• December 6 - General Joubert of the Piedmontese Republic occupies the Sardinian capital of Turin.

  Date unknown

• Edward Jenner publishes An Inquiry into the Causes and Effects of the Variolæ Vaccinæ, describing the smallpox vaccine, in London.
• Thomas Malthus publishes An Essay on the Principle of Population in London.
• Nathan Mayer Rothschild moves from Frankfurt in the Holy Roman Empire to England, settling up in business as a textile trader and financier in Manchester.
• Alois Senefelder invents lithography.
• The first census in Brazil counts 2 million blacks in a total population of 3.25 million.
• The Ayrshire Yeomanry, a British Army Yeomanry Cavalry Regiment, formed by The Earl of Cassillis at Culzean Castle, Ayrshire in 1794, is adopted onto the British Army List.
• The platypus is first discovered by Europeans.

  Births

January

• January 1
• * Ryan Brenan, Australian politician, magistrate and coroner
• * Benjamin Bull, American lawyer and politician
• * Utagawa Kuniyoshi, Japanese artist
• * James Macarthur, pastoralist and politician in New South Wales, Australia
• * Ângelo Carlos Muniz, Brazilian politician
• January 2 – Désiré-Alexandre Batton, French composer
• January 4
• * Paul-Adrien Bourdaloue, French civil engineer
• * William C. Dawson, American politician
• * Robley Dunglison, physician
• January 5
• * David Macbeth Moir, Scottish physician and writer
• * James Semple, American politician from Illinois
• January 6
• * Melchior von Diepenbrock, Catholic cardinal
• * Marie Dorval, French actress
• * Frederick Thellusson, 4th Baron Rendlesham, British politician
• January 7
• * Giovanni Marghinotti, Italian painter
• * Marijan Šunjić, Bosnian Franciscan Catholic bishop, writer, scientific and political worker
• January 8
• * Waddy Thompson Jr., American politician
• * Giuseppe Rosi, Italian poet and patriot
• * Robert Meadows White, English priest
• January 9 – Philippe Joseph Henri Lemaire, French sculptor
• January 10
• * Carl Heinrich Hertwig, German veterinarian
• * David P. Mapes, American politician
• * Federico Sclopis, Italian judge and politician
• January 14
• * Isaac da Costa, Dutch writer, Jewish poet
• * William Duncombe, 2nd Baron Feversham, British politician
• * John Christian Wiltberger Jr., American silversmith and religious activist
• * Robert N. Martin, American politician
• * James Swaby, Jamaican man of colour, one of the first non-white commissioned officers in the British Army
• * Johan Rudolph Thorbecke, Dutch statesman
• January 15
• * Ammon Brown, American politician
• * Thomas Crofton Croker, Irish antiquary and artist
• * Johann Gottlob von Kurr, German pharmacist, botanist and mineralogist
• * Calvary Morris, American politician
• * Samuel Stutchbury, British naturalist
• January 16
• * Chauncey Bulkley, American lawyer
• * Joshua King, British mathematician
• January 17
• * Lea Birch, English cricketer
• * Sir Theodore Brinckman, 1st Baronet, British politician
• * André Friedrich, French sculptor
• * Jean-Baptiste Masui, Belgian engineer
• January 18
• * Augustus Seymour Porter, American politician
• * William Bennett Webster, Canadian politician
• * Christian Whitmer, Book of Mormon witness
• January 19
• * Auguste Comte, French philosopher, pioneer of positivism
• * Samuel Worcester, Christian missionary to Cherokee, civil rights advocate
• January 20
• * Anson Jones, 5th and last President of the Republic of Texas
• * Charles Varin, French writer
• January 21 – Jane Williams, Shelley's muse
• January 22
• * Charles Davies, American mathematician
• * Robert Unwin Harwood, Canadian politician
• * Ciro Menotti, Italian patriot
• January 23 – Joan Cornelis Reynst, Dutch politician
• January 24
• * Henry Addison, American mayor
• * Théodore Caruelle d'Aligny, French painter
• * Karl von Holtei, German actor
• * Karl Georg Christian von Staudt, German geometer
• January 25 – Richard William Jelf, British academic
• January 27
• * George Clarke, New Zealand missionary, teacher, public servant, politician, judge
• * Thekchok Dorje, 14th Karmapa Lama, Tibetan Lama
• * Darius Mead, American politician
• January 28
• * Henry J. Ripley, American baptist clergyman and biblical scholar
• * Marcus Sandys, 3rd Baron Sandys, British politician
• * Basil Manly Sr., American minister
• January 29
• * Patrick Bellew, 1st Baron Bellew, British politician
• * Simeon Borden, American civil engineer
• * Henry Neele, poet
• January 30
• * Manuel Francisco Pavón Aycinena, conservative Guatemalan politician
• * Barker Burnell, American politician
• * Daniel Bailey Ryall, American politician
• January 31
• * Hans Ernst Krøyer, Danish composer
• * Carl Gottlieb Reissiger, German musician
• * John Summerfield, Methodist evangelist, co-founder American Tract Society
• * Ana Gruzinskaya Tolstaya, Georgian princess