A court of impeachment is organized in the United States Senate to hear charges against President Andrew Johnson.

President Andrew Johnson is acquitted in his impeachment trial by one vote in the United States Senate.

Victoria Woodhull becomes the first woman nominated for President of the United States.

Rutherford B. Hayes is privately inaugurated as the 19th President of the United States (his public inauguration coming on March 5).

Women's rights: American President Rutherford B. Hayes signs a bill allowing female attorneys to argue cases before the Supreme Court of the United States.

Charles J. Guiteau shoots and fatally wounds U.S. President James Garfield, who eventually dies from an infection on September 19.

Chester A. Arthur is inaugurated as the 21st President of the United States following the assassination of James Garfield.

Charles J. Guiteau is hanged in Washington, D.C. for the assassination of U.S. President James Garfield.

U.S. President Grover Cleveland marries Frances Folsom in the White House, becoming the only president to wed in the executive mansion.

The Dawes Act authorizes the President of the United States to survey Native American tribal land and divide it into individual allotments.

President Grover Cleveland signs a bill admitting North Dakota, South Dakota, Montana and Washington as U.S. states.

Benjamin Harrison becomes the first President of the United States to attend a baseball game.

The Washington National Cathedral is chartered by Congress. The charter is signed by President Benjamin Harrison.

U.S. President William McKinley signs the Newlands Resolution annexing Hawaii as a territory of the United States.

Anarchist Leon Czolgosz shoots and fatally wounds US President William McKinley at the Pan-American Exposition in Buffalo, New York.

President of the United States William McKinley dies after an assassination attempt on September 6, and is succeeded by Theodore Roosevelt.

Theodore Roosevelt becomes the first President of the United States to ride in an automobile.

President Theodore Roosevelt sends a radio message to King Edward VII: the first transatlantic radio transmission originating in the United States.

Theodore Roosevelt signs the Antiquities Act into law, authorizing the President to restrict the use of certain parcels of public land with historical or conservation value.

Theodore Roosevelt is the first sitting President of the United States to make an official trip outside the country. He did so to inspect progress on the Panama Canal.

U.S. President Theodore Roosevelt wins the Nobel Peace Prize, becoming the first American to win a Nobel Prize.

U.S. President William Taft used what became known as a '''Saxbe fix''', a mechanism to avoid the restriction of the U.S. Constitution's Ineligibility Clause, to appoint Philander C. Knox as U.S. Secretary of State

While campaigning in Milwaukee, Wisconsin, the former President of the United States, Theodore Roosevelt, is shot and mildly wounded by John Schrank, who was angry with Roosevelt for some reason. With the fresh wound in his chest, and the bullet still within it, Mr. Roosevelt still carries out his scheduled public speech.

William H. Van Schaick, captain of the steamship ''General Slocum'' which caught fire and killed over 1,000 people, is pardoned by U.S. President William Howard Taft after three-and-a-half-years in Sing Sing prison.

President Woodrow Wilson addresses American Civil War veterans at the Great Reunion of 1913.

President Woodrow Wilson triggers the explosion of the Gamboa Dike thus ending construction on the Panama Canal.

The Federal Reserve Act is signed into law by President Woodrow Wilson, creating the Federal Reserve.

President Woodrow Wilson sends 12,000 United States troops over the U.S.-Mexico border to pursue Pancho Villa.

World War I: President Woodrow Wilson of the still-neutral United States calls for "peace without victory" in Europe.

The Congress of the United States passes the Immigration Act of 1917 over President Woodrow Wilson's veto. Also known as the ''Asiatic Barred Zone Act'', it forbade immigration from nearly all of south and southeast Asia.

World War I: President Woodrow Wilson asks the U.S. Congress for a declaration of war on Germany.

World War I: The Selective Service Act of 1917 is passed, giving the President of the United States the power of conscription.

U.S. President Woodrow Wilson sails for the World War I peace talks in Versailles, becoming the first US president to travel to Europe while in office.

U.S. President Woodrow Wilson suffers a massive stroke, leaving him partially paralyzed.

Former U.S. President William Howard Taft is sworn in as 10th Chief Justice of the U.S. Supreme Court, becoming the only person to ever be both President and Chief Justice.

President Warren G. Harding introduces the first radio in the White House.

Calvin Coolidge is sworn in as the 30th President of the United States in the early morning following the death of Warren G. Harding the previous day.

Calvin Coolidge becomes the first President of the United States to deliver a political speech on radio.

''TIME'' magazine features eccentric American politician William "Alfalfa" Murray on its cover after Murray stated his intention to run for President of the United States.

U.S. President Herbert Hoover orders the United States Army to forcibly evict the "Bonus Army" of World War I veterans gathered in Washington, D.C.