1908
The U.S. Bureau of Investigation is created in 1908 by U.S. Attorney General Charles Joseph Bonaparte, “although another year passed” before it is christened with that name. It became known as the FBI in 1935. (Curt Gentry, J. Edgar Hoover: The Man and the Secrets, (NY: W.W. Norton, 1991), p. 70, 113.)

1910
The White Slave Traffic Act, introduced by Congressman James Robert Mann of Illinois, is aimed at the traffic in foreign-born prostitutes. (Gentry, J. Edgar Hoover, p. 114.)

1914, July 28
The Great War (also known as the War to End All Wars, and, later, as World War One) starts with Austria-Hungary declaring war on Serbia. On August 1, Germany declared war on Russia. Germany then sent its army through Belgium to attack Russia’s ally, France, also bringing Great Britain into the war. This global war that lasted four years, to November 11, 1918. (History.com accessed April 2, 2018 from: https://www.history.com/topics/world-war-i/outbreak-of-world-war-i)

1917
A history of the FBI, by two agents, is quoted as claiming that the General Intelligence Division of the Bureau of Investigation was organized "under the direct administrative supervision of J. Edgar Hoover since 1917 in charge of counter-radical activities as special assistant to the attorney general." (Gentry, J. Edgar Hoover, p. 73)

1917, February 5
A revamped U.S. immigration law, passed by the U.S. Congress, serves as an effective weapon in the hands of officials aligned against radical, activist immigrants. (A copy of the original law was accessed April 3, 2018 from: http://library.uwb.edu/Static/USimmigration/39%20stat%20874.pdf)

1917, April 2
U.S. President Woodrow Wilson goes before Congress to pledge the nation’s resources to help the Allies (France, Britain, Russia, Italy, and Japan) defeat the Central Powers (Germany, Austria-Hungary and the Ottoman Empire). (History.com accessed April 2, 2018, from https://www.history.com/this-day-in-history/u-s-congress-passes-selective-service-act

1917, April 6
The U.S. enters the Great War. (Gentry, J. Edgar Hoover, p. 68; History.com accessed April 2, 2018, from: https://www.history.com/this-day-in-history/u-s-enters-world-war-i)

1917, May 18
The U.S. Congress passes The Selective Service Act requiring all males between 21 and 30 register for the draft, and giving the U.S. president the power to draft soldiers.(Gentry, J. Edgar Hoover, p. 71)

1917, June 15
The U.S. Congress passes the Espionage Act after America’s formal entrance into World War I against Germany. The Espionage Act makes it a crime for any person to convey information intended to interfere with the U.S. armed forces prosecution of the war effort or to promote the success of the country’s enemies. Anyone found guilty of such acts is subject to a fine of $10,000 and a prison sentence of 20 years. (Gentry, J. Edgar Hoover, p. 70; History.com accessed April 2, 2018, from https://www.history.com/this-day-in-history/u-s-congress-passes-espionage-act)

1917, July 26
John Edgar Hoover, 22, accepts a clerkship in the U.S. Department of Justice, a draft-exempt job. Less than three months after Hoover's arrival, he is promoted, and three months later promoted again. He is placed in charge of a unit in the Enemy Alien Registration Section of the Justice Department. (Gentry, J. Edgar Hoover, p. 69.)

1917, September 5
Bureau of Investigation agents, assisted by members of the vigilante group, the American Protective League, conduct simultaneous raids on headquarters of the International Workers of the World (IWW) in 24 U.S. cities. (Gentry, J. Edgar Hoover, p. 71)

1917, November 7
Russian revolution. (Gentry, J. Edgar Hoover, p. 76)

1918, April 16
The U.S. Congress amends the Alien Enemies act to include female as well as male enemies. (Accessed April 2, 2018 from: http://uscode.house.gov/view.xhtml?path=/prelim@title50/chapter3&edition=prelim)

1918, May 16
The U.S. Congress passes the Sedition Act. Engineered mainly by U.S. Attorney General A. Mitchell Palmer, the act makes it a crime for any person to convey information intended to interfere with the U.S. armed forces’ prosecution of the war effort or to promote the success of the country’s enemies. Aimed at socialists, pacifists and other anti-war activists, the Sedition Act imposed harsh penalties on anyone found guilty of making false statements that interfered with the prosecution of the war; insulting or abusing the U.S. government, the flag, the U.S. Constitution, or the military; agitating against the production of necessary war materials; or advocating, teaching or defending any of these acts. (History.com accessed April 2, 2018, from: https://www.history.com/this-day-in-history/u-s-congress-passes-sedition-act)

1918, November 18
Socialist Eugene V. Debs is sentenced to ten years in prison. On June 16, 1918, Debs had made a speech in Canton, Ohio, urging resistance to the military draft of World War I. Debs was arrested on June 30 and charged with ten counts of sedition. (Eugene V. Debs, Wikipedia, accessed March 7, 2018, from: 
https://en.wikipedia.org/wiki/Eugene_V._Debs#Incarceration)

1919, June 2
At about eleven-fifteen, at night a bomb goes off at the home of the new attorney general A. Mitchell Palmer, in Washington, D.C. (Gentry, J. Edgar Hoover, p. 74)

1919, June 17
Attorney General A. Mitchell Palmer holds an all-day meeting with Francis P. Garvan, the attorney general's chief investigator, William J. Flynn, Bureau of Investigation chief, and their assistants. The best way to deal with the new menace will be a mass round-up of and deportation of alien radicals. (Gentry, J. Edgar Hoover, p. 77-78)

1919, August 1
Attorney General A. Mitchell Palmer appoints 24-year-old J. Edgar Hoover, special assistant to the attorney general, chief of a new division of the Justice Department's Bureau of Investigation, the General Intelligence Division. It will investigate the programs of radical groups and identify their members. (Curt Gentry, J. Edgar Hoover, page 79.)

1919, August 12
William J. Flynn, Bureau of Investigation chief, sends a confidential letter to "all special agents and employees" (a  euphemism for undercover operatives). ordering "a vigorous and comprehensive investigation" of all anarchists, Bolsheviks, and "kindred agitations." He states that investigations should be directed particularly to aliens, for the purpose of developing deportation cases. Flynn adds: "You will also make full investigation of similar activities of citizens of the United States . . . ." (Curt Gentry, J. Edgar Hoover, page 80.) 

1919, September 3
Thirty-five Bureau of Investigation agents, 2,000 members of the American Protective League, 2000 military personnel, and several hundred policemen in New York City, Brooklyn, Jersey City, and Newark, stop and search men, demanding that each produce either a draft registration card or a birth certificate proving him to young or too old or the draft. (Gentry, J. Edgar Hoover, p. 72.)

1919, November 7
On this date, chosen because it was the second anniversary of the Bolshevik revolution, agents of the Bureau of Investigation, together with local police, executed a series of well-publicized and violent raids against Russian workers in 12 cities. (Gentry, J. Edgar Hoover, p. 83)

The Palmer Raids were attempts by the United States Department of Justice to arrest and deport radical leftists, especially anarchists, from the United States. Further raids and arrests occurred in November 1919 and January 1920 under the leadership of Attorney General A. Mitchell Palmer.(Wikipedia: Palmer Raids; Preparations. http://en.wikipedia.org/wiki/Palmer_Raids#Preparations+