1911 in the United States

Federal government

• President: William Howard Taft (R-Ohio)
• Vice President: James S. Sherman (R-New York)
• Chief Justice: Edward Douglass White (Louisiana)
• Speaker of the House of Representatives:

Joseph Gurney Cannon (R-Illinois) (until March 4)

Champ Clark (D-Missouri) (starting April 4)

• Congress: 61st (until March 4), 62nd (starting March 4)

January–March

• January 5 – The Kappa Alpha Psi fraternity is founded at Indiana University, Bloomington, Indiana.
• January 17 – Emmet O'Neal is sworn in as the 34th governor of Alabama replacing B. B. Comer.
• January 18 – Eugene Burton Ely lands on the deck of the USS Pennsylvania stationed in San Francisco Bay, marking the first time an aircraft lands on a ship.
• January 30 – The destroyer USS Terry makes the first aeroplane rescue at sea, saving the life of John McCurdy 10 miles from Havana, Cuba.
• January – The Masses socialist magazine begins publication.
• February 5 – The Missouri State Capitol building in Jefferson City, Missouri is destroyed by fire after a bolt of lightning strikes the dome.
• March – The first installment of a serialized version of Frederick Winslow Taylor's monograph, The Principles of Scientific Management, appears in The American Magazine. The complete series runs in the March, April, and May issues, giving a boost to the efficiency movement.^[1]
• March 10 – The Kansas legislature approves House Bill Number 906, effectively the first blue sky law in the United States, culminating an effort by Joseph Norman Dolley, Kansas' banking commissioner.
• March 25 – The Triangle Shirtwaist Factory fire in New York City kills 146.
• March 29 – The United States Army formally adopts the M1911 pistol as its standard sidearm, thus giving the gun its 1911 designation.

April–June

• April 13 – Mexican Revolution: Rebels take Agua Prieta on the Sonora–Arizona border; government troops take the town back April 17 when the rebel leader "Red" López is drunk.
• April 17 – Southern Methodist University is chartered in Dallas, Texas.
• April 27 – Following the resignation and death of William P. Frye, a compromise is reached to rotate the office of President pro tempore of the United States Senate.
• April 30 – Sparks from a burning hayshed ignite the Great Fire of 1911, destroying much of downtown Bangor, Maine.
• May 15 – The U.S. Supreme Court declares Standard Oil to be an "unreasonable" monopoly under the Sherman Antitrust Act and orders the company to be dissolved.
• May 23 – The main branch of the New York Public Library is officially opened.
• May 24 – Colorado National Monument is established.
• May 30 – The first Indianapolis 500-mile auto race is run. The winner is Ray Harroun in the Marmon 'Wasp.'
• June 5 – Charles F. Kettering files US patent 1,150,523, for an electric Engine Starting Device.
• June 16
  • A 772-gram stony meteorite strikes earth in Columbia County, Wisconsin, near the village of Kilbourn, damaging a barn.
  • IBM is incorporated as the Computing-Tabulating-Recording Company in Endicott, New York.
• July 24 – Hiram Bingham rediscovers Machu Picchu.

July–September

• August 8 – Public Law 62-5 sets the number of representatives in the United States House of Representatives at 435 (the law takes effect in 1913).
• August 29 – Ishi, last known member of the Yana people, leaves the California wilderness.
• September 11 – Middle Tennessee State University is founded in Murfreesboro, Tennessee, as Middle Tennessee Normal School.
• September 25 – Groundbreaking for Fenway Park in Boston, Massachusetts, begins.
• September 30 – Austin Dam breaks, wiping out the town of Austin, Pennsylvania, and continuing downstream about 8 miles into the village of Costello.

October–December

• October 7 – Outlaw Elmer McCurdy and "associates" are chased after trying to rob a train in Oklahoma. McCurdy on the run is eventually hunted down and shot by authorities. His body is never claimed and later is chemically petrified. Afterwards his remains serve as sideshow attractions in carnivals until 1976 when they are diagnosed by forensic experts to be McCurdy. McCurdy's body is finally buried in 1976 after a 65-year odyssey to the grave.
• October 24 – Orville Wright remains in the air 9 minutes and 45 seconds in a glider at Kill Devil Hills, North Carolina, setting a new world record that stands for 10 years.^[2]
• October 26 – In baseball, the Philadelphia Athletics defeat the New York Giants, 13–2, to win the 1911 World Series in six games. The game is tied 1–1 after three innings, but with four runs in the fourth, and seven runs in the seventh, the As demolish the Giants.
• October 28 – The Rosicrucian Fellowship's international headquarters opens at Mount Ecclesia, Oceanside, California (preceded by its formal constitution on August 8, 1909, at Seattle, Washington).
• November 3 – Chevrolet officially enters the automobile market to compete with the Ford Model T.
• November 11
  • The Great Blue Norther of 11/11/11: A record cold snap hits the United States Midwest; many cities break record highs and lows on the same day.
  • The Upton Machine Company, now Whirlpool Corporation, was founded in St Joseph, MI.
• November 17 – The Omega Psi Phi fraternity is founded at Howard University.
• December 24 – The Lackawanna Cutoff, the first of two major cutoffs built by the Delaware, Lackawanna and Western Railroad, opens just 3 years after it was built.

Ongoing

• Progressive Era (1890s–1920s)
• Lochner era (c. 1897–c. 1937)