The book combines material from Zinn's history book A People's History of the United States and his autobiography You Can't Be Neutral on a Moving Train with new material from other sources, most notably George Lipsitz's A Rainbow at Midnight: Labor and Culture in the 1940s and Jim Zwick's Mark Twain's Weapons of Satire: Anti-Imperialist Writings on the Philippine-American War.

Various people who were involved in the events of the war and those leading up to it are discussed, such as Antonio Maceo Grajales, Máximo Gómez, José Martí, Clemencia Arango.

Other topics covered include the media hype for the war created by William Randolph Hearst's New York Journal and Joseph Pulitzer's New York World (which led to the concept of yellow journalism); the explosion of the USS Maine, which the two newspapers blamed on the Spanish; the actions of labor unions, which supported the Cuban rebels but not U.S. intervention; the Black 25th Infantry and its experience with racism at the hands of the Rough Riders; the poisoning of soldiers by spoiled meat packaged by Armour and Co.; and the takeover of Cuba by the U.S. and Chapter III, "The Invasion of the Philippines", covers the events of the Philippine–American War.

Other topics and individuals covered include George Dewey, Fermín Jáudenes, Fort San Antonio de Abad, the Benevolent Assimilation Proclamation, the battle of Santa Mesa, William Jennings Bryan, Albert J. Beveridge, Henry M. Turner, W. E. B.

Du Bois, Littletown Waller, the shootings at Samar, Elihu Root, Theodore Roosevelt, the use of the water cure in the war, Leonard Wood, the Moro Crater massacre, Mark Twain, and the Anti-Imperialist League.

It begins with discussing how the U.S. government used its military power to protect American business interests both within the country and abroad during such events as the aftermath of the Mexican Revolution and the Ludlow Massacre.

Other topics and individuals covered include Woodrow Wilson, Randolph Bourne, Robert Lansing, Bernard Baruch, William Gibbs McAdoo, the Lusitania, the Sykes–Picot Agreement, the Conscription Act of 1917, the Espionage Act of 1917, Champ Clark, the American Protective League, the Industrial Workers of the World, Camp Funston, Sheldon W. Smith, Leavenworth Prison, Kate Richards O'Hare, Alice Paul, the National Women's Party, and Emma Goldman.