In 1881 Lewis decided to give up his legal work to become a journalist. This included being editor of the Mora County Pioneer in New Mexico and editor of the Las Vegas Optic. He moved to Kansas City where he contributed articles and short stories to the Kansas City Times.
In 1891 Lewis became a journalist in Washington and was employed as a staff reporter on the Chicago Times. Later he became editor of the Chicago Times-Herald. He also published his first book, Woolfville: Episodes of Cowboy Life (1893). Lewis also wrote about social issues. This included The Boss (1903) a story about the corruption of politics in New York City. He also wrote about this subject for Cosmopolitan Magazine. This included an attack on the International Harvester Company, asserting that the trust was killing competition and stifling invention.
In June, 1908, Lewis began a series of articles on USA's leading businessmen called the Owners of America (1908 - 1909). He explained how these men controlled the political process. For example, he argued that Thomas F. Ryan had complete political control over certain cities: "Mayors are his office-boys, governors come and go at his call. He possesses himself a party and selects a candidate for the presidency. Tammany Hall is a dog for his hunting, and he breaks city council to his money-will as folk break horses to harness".
Other articles by Lewis published in Cosmopolitan Magazine were A Trust in Agricultural Implements, April, 1905; The Trail of the Viper, April, 1911 and The Viper's Trail of Gold, May, 1911. Lewis also took a keen interest in the conservation of natural resources. In 1909 he wrote a series of articles about what was taking place in Alaska for Pearson's Magazine called The Betrayal of a Nation.
Alfred Henry Lewis died of intestinal problems on 23rd December 1914. Some of his stories were later turned into films. This included The Tenderfoot (1917), Tucson Jennie's Heart (1918), The Coming of Faro Nell (1918), Rose of Wolfville (1918), The Clients of Aaron Green (1918) and The Trials of Texas Thompson (1919).
What is he? Nothing! What has he done? Nothing! Who will remember him? No one! He is a weak, vain, troubled, unhappy, unrespected man. The country owes him nothing, for he has given it nothing. One day he will die; and his epitaph might truthfully be, "He publicly came to nothing, and privately came to grief."
Mayors are his office-boys, governors come and go at his call. He possesses himself a party and selects a candidate for the presidency. Tammany Hall is a dog for his hunting, and he breaks city council to his money-will as folk break horses to harness