• The Greek War of Independence rages. Egyptian general Ibrahim Pasha captures Greece's Morea peninsula.
• The Russo-Persian War erupts.
• The Javanese revolt against the Dutch under Prince Diponegoro.
• Russian army officers demanding social reforms lead the abortive Decembrist Revolt against the new Czar, Nicholas I.
• The US House of Representatives elects John Quincy Adams the 6th president of the United States after no candidate receives a majority of the electoral votes.
• Bolivia becomes independent from Spain.
• Uruguay declares independence from Brazil.
• The Erie Canal opens, linking the Great Lakes to the Atlantic via the Hudson River
• The first passenger train runs through Darlington, England on the the Stockton and Darlington Railway.
• André-Marie Ampčre demonstrates that a current-carrying conductor will exert a force on a magnet and vice versa.
• Vancouver is founded by the Hudson's Bay Company as Fort Vancouver.

These people were born in 1825:

• Viennese musician Johann Strauss, composer of famous waltzes such as The Blue Danube.
• Indian nationalist Dadabhai Naoroji.
• Pedro II, future emperor of Brazil.
• "Darwin's Bulldog" Thomas Henry Huxley.
• Confederate general George E. Pickett, leader of ill-fated "Pickett's Charge" at Gettysburg.
• Hungarian romantic novelist Mór Jókai.
• American statesman Lucius Quintus Cincinnatus Lamar.
• American landscape painter George Inness.
• German chemist Richard Erlenmeyer, inventor of the Erlenmeyer flask.
• French academic painter Adolphe-William Bouguereau.
• English novelist Richard Doddridge Blackmore.

These people died in 1825:

• Russian Tsar Alexander I. He is succeeded by his son, Nicholas I.
• French painter Jacques-Louis David.
• Italian composer Antonio Salieri.
• Cotton gin inventor Eli Whitney.
• Japanese print artist Toyokuni Utagawa.
• American statesman Charles Cotesworth Pinckney.
• English poet Anna Letitia Barbauld.
• James Monroe's vice president, Daniel D. Tompkins.

1824 - 1825 - 1826

19th century