American muckraker Ray Stannard Baker, who served as head of the Press Bureau for the American Commission at the Paris Peace Conference, shown here with President Woodrow Wilson in Paris, 1919. (BROWN BROTHERS)

The streets of Boston in the aftermath of the January 15, 1919, explosion of a tank holding 2.3 million tons of fermenting molasses intended for use in the manufacture of munitions and alcoholic beverages; a viscous wave 25 feet high and 160 feet wide moved through the streets of Boston’s industrial north. (BOSTON PUBLIC LIBRARY)

Alice Paul, who organized the “watchfires of freedom” demonstration for the cause of women’s suffrage in January 1919, shown here sewing a star on the National Woman’s Party flag to indicate that yet another state had ratified the 19th Amendment. (LIBRARY OF CONGRESS)

American journalist and poet Carl Sandburg at his desk in Chicago in 1918. (NATIONAL PARK SERVICE PHOTO)

Madam C. J. Walker, millionaire businesswoman, shown here at a meeting held at the Waldorf-Astoria Hotel, New York City, on January 17, 1919, to discuss plans for working with the Japanese in Paris to advocate racial justice at the Peace Conference. (A’LELIA BUNDLES, MADAM WALKER FAMILY COLLECTION)

William Monroe Trotter, founder in 1901 of The Guardian, an African-American newspaper in Boston. An outspoken journalist, he sought “real democracy” for African-Americans in Paris during the Peace Conference of 1919. (THE WILLIAM MONROE TROTTER INSTITUTE, UNIVERSITY OF MASSACHUSETTS)

W. E. B. Du Bois, considered the foremost African-American intellectual of the 20th century; editor of The Crisis magazine from 1910 to 1934 and head of the Pan-African Congress held in Paris in February 1919. (LIBRARY OF CONGRESS)

A political cartoon expressing the frustration of African-Americans in the aftermath of World War I and the hypocrisy of Woodrow Wilson’s campaign to make the world “safe for democracy.” (NEW YORK AGE, AUGUST 9, 1919)

The streets of New York City on February 17, 1919, when two million spectators lined Fifth Avenue from 53rd Street to the corner of 145th Street and Lenox Avenue in Harlem to hail the return of “Harlem’s Own” 369th U.S. Infantry. (LIBRARY OF CONGRESS)

Sgt. Henry Johnson, the Pullman porter from Albany, New York, who fought in the 369th U.S. Infantry and was the first American soldier to earn the Croix de Guerre in World War I. (ALBANY, NY, TIMES-UNION)

Major Walter H. Loving, who served the U.S. War Department’s Military Intelligence Division as head of a covert investigation of “negro subversion” from fall 1917 through August 1919. (HOWARD UNIVERSITY)

James Weldon Johnson, author, musician, and promoter of African-American literature and art; he wrote a New York Age column, “Views and Reviews,” in 1919 and became executive secretary of the NAACP the following year. (LIBRARY OF CONGRESS)

The burning of the lynched African-American William Brown in Omaha, Nebraska, September 28, 1919. (BROWN BROTHERS)

An American soldier of Company I, 339th U.S. Infantry, known as the “Polar Bears,” stationed in northern Russia; photo is dated February 17, 1919, when the temperature was fifty degrees below zero. (MICHIGAN’S OWN MILITARY AND SPACE MUSEUM)

Hiram Johnson, Republican Senator from California and first politician to publicly challenge the continued presence of U.S. troops in northern Russia after the Armistice. (LIBRARY OF CONGRESS)

Harry Weinberger, New York City attorney known for his dedication to civil liberties. He represented radicals and immigrants such as Mollie Steimer and Jacob Abrams. (COLLECTION OF WARREN WEINBERGER)

Oliver Wendell Holmes, Jr., associate justice of the Supreme Court, renowned for his “clear and present danger” ruling of 1919 on the limitations of free speech, and for his dissent later that year in the Abrams case, considered a benchmark in modern free speech law. (LIBRARY OF CONGRESS)

Mollie Steimer, Russian immigrant sentenced to 15 years in prison for distributing leaflets to protest America’s postwar intervention in northern Russia. (TAMIMENT LIBRARY, NEW YORK UNIVERSITY)

A young J. Edgar Hoover at his Department of Justice desk in the early 1920s. August 1, 1919, was Hoover’s first day on the job as director of the General Intelligence Division of the Bureau of Investigation, now known as the FBI. (LIBRARY OF CONGRESS)

A. Mitchell Palmer, attorney general in 1919. (LIBRARY OF CONGRESS)

The façade of Palmer’s house at 2132 R Street in Washington, D.C., after the June 2, 1919, bombing. (LIBRARY OF CONGRESS)

Albert Einstein with the acclaimed British astronomer Sir Arthur Stanley Eddington in the early 1930s. (SYNDICS OF CAMBRIDGE UNIVERSITY LIBRARY)

British pilot Sir John Alcock and American navigator Sir Arthur Brown, aviators who together made the first nonstop transatlantic flight in June 1919. (CYNTHIA LONG, ALCOCK AND BROWN VICKERS PLC COLLECTION)

Helen Keller on horseback in Beverly Hills, California, in August of 1919, the same month in which her movie Deliverance was released. (HELEN KELLER ARCHIVES, THE AMERICAN FOUNDATION FOR THE BLIND)

Scene from a play produced by the Actors’ Equity Association after their walkout in August 1919, the first strike in the history of the American theater. (TAMIMENT LIBRARY, NEW YORK UNIVERSITY)

Judge Elbert H. Gary, chairman of United States Steel Corporation, speaking to steelworkers in Gary, Indiana, on September 19, 1919, three days before the nationwide steel strike. John A. Fitzpatrick, president of the Chicago Federation of Labor, is seen behind Gary. (BROWN BROTHERS)