In 1872, Lloyd joined the staff of the Chicago Tribune, gaining promotion to the position of chief editorial writer in 1875. He remained at the paper until 1885. Lloyd was one of the precursors to the later muckraker journalists, writing a searing exposé of the monopolistic abuses of John D. Rockefeller's Standard Oil Trust, "The Story of a Great Monopoly," published in the March 1881 issue of The Atlantic. He later fleshed out his case against the unbridled corporate power of Standard Oil and similar corporations in his best-known book, Wealth Against Commonwealth, published in 1894. Lloyd's work thus preceded Ida Tarbell's more famous 1904 work, "The History of Standard Oil," by a number of years.
Political career
As a political activist, Lloyd defended the Haymarket anarchists in 1886, a position that caused his father-in-law, William Bross, publisher of the Tribune, to disinherit him and his wife Jessie Bross. However, William Bross and his only daughter must have made amends, because he died in her home. Lloyd, after leaving the newspaper, continued to file stories as a free-lancing dispatcher, using the Associated Press wires, and his publications of outrage over the treatment of miners in the Spring Valley dispute are credited with ending that episode. Lloyd also wrote and spoke on behalf of Milwaukeestreetcar operators in 1893, and anthracite coal miners in 1902. Lloyd was a leading citizen of Winnetka, Illinois. Elected more than once as a Village trustee and member of the Boardof Education, he served as vice-president of the Village council from 1884 to 1886, and as Village treasurer in 1887 and 1888. He was president of the Town Meeting in 1898 and is credited with a leading role in pioneering what became known nationally as the "Winnetka system" of self-government, a reform cause broadly taken up by Samuel Gompers and the labor movement. In 1894, Lloyd ran for United States Congress as a candidate of the People's Party, the so-called "Populists." In subsequent years he was supportive of the aims of the Socialist Party of America, although he was never an active member of the organization.
"As the Standard Oil article in the Atlantic became the armory of every person willing to fight for industrial freedom, so Wealth Against Commonwealth in later years became the great storehouse of information to which numbers of able campaigners habitually resorted for their facts. Probably millions of men read or heard Mr. Lloyd's ideas without being aware of the real authorship. But I judge that with this condition he was well content. No man ever entered such a fight with a smaller share of personal vanity to gratify. He desired that his countrymen should be informed of existing conditions, but not that he himself should gain fame or rewards."