Timeline of United States history (1900–1929)
This section of the Timeline of United States history concerns events from 1900 to 1929.
1900s
Presidency of William McKinley
- 1900 – U.S. population exceeds 75 million
- 1900 – U.S. helps put down Boxer Rebellion
- 1900 – 1900 Galveston hurricane
- 1900 – U.S. presidential election, 1900: William McKinley reelected president; Theodore Roosevelt elected vice president
- 1901 – President McKinley begins second term, Theodore Roosevelt becomes Vice President
- 1900 - the first man to ceres an ape
Presidency of Theodore Roosevelt
- 1901 – President McKinley assassinated, Vice President Roosevelt becomes the 26th President
- 1901 – U.S. Steel founded by John Pierpont Morgan
- 1901 – Hay-Pauncefote Treaty
- 1901 – Walt Disney born
- 1902 – Drago Doctrine
- 1902 – First Rose Bowl game played
- 1902 – Newlands Reclamation Act
- 1903 – Great Train Robbery movie opens
- 1903 – Harley-Davidson Motor Company created
- 1903 – Ford Motor Company formed
- 1903 – First World Series
- 1903 – Elkins Act
- 1903 – Big Stick Diplomacy
- 1903 – Hay-Bunau-Varilla Treaty
- 1903 – Hay-Herrán Treaty
- 1903 – Department of Commerce and Labor created
- 1903 – The Wright brothers make their first powered flight in the Wright Flyer at Kitty Hawk, North Carolina
- 1904 – Roosevelt Corollary to Monroe Doctrine
- 1904 – Panama Canal Zone acquired
- 1904 – World's Fair St. Louis
- 1904 – U.S. presidential election, 1904: Theodore Roosevelt elected president for full term; Charles W. Fairbanks elected vice president
- 1905 – President Roosevelt begins full term, Charles W. Fairbanks becomes Vice President
- 1905 – Niagara Falls conference
- 1905 – Industrial Workers of the World
- 1905 – Albert Einstein publishes his Theory of Relativity
- 1906 – Susan B. Anthony dies
- 1906 – Algeciras Conference
- 1906 – Pure Food and Drug Act and Meat Inspection Act
- 1906 – Hepburn Act
- 1906 – Theodore Roosevelt negotiates Treaty of Portsmouth, receives Nobel Peace Prize
- 1906 – San Francisco earthquake
- 1907 – Oklahoma becomes a state
- 1907 – Gentlemen's Agreement
- 1907 – Coal mine explodes in Monongah, West Virginia, killing at least 361. Worst industrial accident in American history.
- 1908 – Ford Model T appears on market
- 1908 – Root-Takahira Agreement
- 1908 – Federal Bureau of Investigation established
- 1908 – Aldrich-Vreeland Act
- 1908 – U.S. presidential election, 1908: William Howard Taft elected president; James S. Sherman vice president. William Jennings Bryan loses for the third and final time.
- 1909 – The U.S. penny is changed to the Abraham Lincoln design
Presidency of William Howard Taft
- 1909 – William Howard Taft becomes the 27th President, James S. Sherman becomes Vice President
- 1909 – Robert Peary claims to have reached the North Pole
- 1909 – NAACP founded by W. E. B. Du Bois
- 1909 – Payne–Aldrich Tariff Act
- 1909 – Taft implements dollar diplomacy
- 1909 – Pinchot–Ballinger controversy
1910s
- 1910 – Mann–Elkins Act
- 1910 – Mann Act
- 1911 – Supreme Court breaks up Standard Oil
- 1911 – Triangle Shirtwaist Factory fire
- 1911 – First Indianapolis 500 is staged; Ray Harroun is the first winner
- 1912 – RMS Titanic sinks
- 1912 – New Mexico and Arizona become states
- 1912 – Girl Scouts of the USA was started by Juliette Gordon Low
- 1912 – Theodore Roosevelt shot, but not killed, while campaigning for the bull Moose Party
- 1912 – Vice President Sherman dies
- 1912 – U.S. presidential election, 1912: Woodrow Wilson elected president, Thomas R. Marshall, vice president. Roosevelt becomes the only third party candidate to come in second for well over a century.
Presidency of Woodrow Wilson
- 1913 – Wilson becomes the 28th President and Marshall, Vice President
- 1913 – Woman Suffrage Procession, a large woman suffrage parade in Washington D.C., is organized by Alice Paul and held on the eve of Wilson's inaugural
- 1913 – 16th Amendment, establishing an income tax
- 1913 – End of the Philippine–American War
- 1913 – The Armory Show opens in New York City introducing Modern art both American and European to the American public.
- 1913 – 17th Amendment, establishing direct election of U.S. Senators.
- 1913 – Underwood Tariff
- 1913 – Henry Ford develops the modern assembly line
- 1914 – Mother's Day established as a national holiday
- 1914 – Federal Trade Commission created
- 1914 – Clayton Antitrust Act
- 1914 – ABC Powers
- 1915 – The Birth of a Nation opens
- 1915 – RMS Lusitania sunk
- 1916 – U.S. acquires Virgin Islands
- 1916 – Jeannette Rankin first woman elected to U.S. congress
- 1916 – Louis Brandeis appointed to Supreme Court
- 1916 – Adamson Railway Labor Act
- 1916 – Federal Farm Loan Act
- 1916 – Jones Act
- 1916 – 1916 United States presidential election: Wilson and Marshall reelected by a mere 3,773 votes in California
- 1917 – Zimmermann Telegram
- 1917 – President Wilson and Vice President Marshall begin second terms
- 1917 – U.S. enters World War I
- 1917 – Espionage and Sedition Acts
- 1917 – Lansing–Ishii Agreement
- 1917 – National Hockey League formed
- 1917 – U.S. Virgin Islands purchased from Denmark
- 1917–1919 – Silent Sentinels hold a vigil outside the White House gates in favor of women's suffrage, a nearly two-and-a-half year demonstration organized by Alice Paul and the National Woman's Party
- 1917–1920 – First Red Scare, marked by a widespread fear of Bolshevism and anarchism
- 1918 – President Wilson's Fourteen Points, which assures citizens that the Great War was being fought for a moral cause and for postwar peace in Europe
- 1918 – Republicans win back congress in the Midterm elections.
- 1918 – Armistice agreement ends World War I
- 1918 – Spanish flu pandemic begins
- 1919 – Treaty of Versailles agreed to by victorious powers.
- 1919 – President Wilson has massive stroke. First Lady Edith Wilson takes over in a "silent coup".
- 1919 – United States Senate rejects Treaty of Versailles and League of Nations
- 1919 – 18th Amendment, establishing Prohibition
- 1919 – Black Sox Scandal during that year's World Series, with the fallout lasting for decades
1920s
- 1920 – 19th Amendment, grants women the right to vote
- 1920 – Sacco and Vanzetti arrested
- 1920 – First radio broadcasts, by KDKA in Pittsburgh and WWJ in Detroit
- 1920 – Volstead Act
- 1920 – Esch–Cummins Act
- 1920 – Economy collapses. Depression of 1920–21 begins.
- 1920 – National Football League is formed
- 1920 – U.S. presidential election, 1920: Warren G. Harding elected president, and Calvin Coolidge vice president.
Presidency of Warren G.Harding
- 1921 – Harding becomes the 29th President and Coolidge Vice President
- 1921 – Washington Disarmament Conference of 1921
- 1921 – Emergency Quota Act
- 1922 – Fordney–McCumber Tariff
Presidency of J. Calvin Coolidge
- 1923 – President Harding dies; Vice President Coolidge becomes the 30th President
- 1923 – Teapot Dome scandal
- 1924 – Immigration Act Basic Law
- 1924 – J. Edgar Hoover is appointed director of the Bureau of Investigation — predecessor to the FBI.
- 1924 – U.S. presidential election, 1924: Calvin Coolidge elected president for a full term, Charles G. Dawes elected vice president
- 1925 – President Coolidge begins full term, Charles G. Dawes becomes Vice President
- 1925 – Scopes Trial, whose outcome found that the teaching of evolution in the classroom "does not violate church and state or state religion laws but instead, merely prohibits the teaching of evolution on the grounds of intellectual disagreement"
- 1925 – Nellie Tayloe Ross elected governor of Wyoming
- 1925 – WSM broadcasts the Grand Ole Opry for the first time.
- 1926 – NBC founded as the U.S.'s first major broadcast network
- 1927 – Sacco and Vanzetti executed, seven years after they were convicted of murdering two men during an armed robbery in Massachusetts
- 1927 – Charles Lindbergh makes first trans-Atlantic flight
- 1927 – The Jazz Singer, the first motion picture with sound, is released
- 1927 – U.S. citizenship granted to inhabitants of U.S. Virgin Islands
- 1927 – Columbia Broadcasting System was founded, becomes second national radio network in the U.S.
- 1928 – Disney's Steamboat Willie opens, the first animated picture to feature Mickey Mouse
- 1928 – Kellogg–Briand Pact
- 1928 – Amelia Earhart becomes the first woman to fly solo across the Atlantic Ocean.
- 1928 – U.S. presidential election, 1928: Herbert C. Hoover elected president and Charles Curtis vice president
- 1929 – St. Valentine's Day Massacre
Presidency of Herbert C. Hoover
- 1929 – Herbert C. Hoover becomes the 31st President, Charles Curtis becomes the Vice President
- 1929 – Immigration Act
- 1929 – The Dow Jones Industrial Average plummets a record 68 points over a two-day period, setting off the Wall Street Crash of 1929 and triggering the Great Depression
- 1929 – The Museum of Modern Art opens to the public in New York City
- 1929 – American Samoa officially becomes a U.S. territory
- 1929 – The Great Depression starts