In 1895 he became managing editor of the Cosmopolitan Magazine; but in less than a year he retired that he might have more time for writing.
Previously to their holding office, Daniel Manning (1831-1887), secretary of the treasury in President Cleveland's cabinet, was president of the Argus company, and Daniel Scott Lamont (1851-1905), secretary of war during President Cleveland's second administration, was managing editor of the newspaper.
He graduated at Union College in 1835, practised law in New York for several years after 1839; took up journalistic work; was joint owner (with William Cullen Bryant) and managing editor of the New York Evening Post (1849-1861); was United States consul at Paris in 1861-1864, and was minister to France in 1864-1867.
After working on several papers he served as managing editor of Harper's Weekly.
His brother George Cary Eggleston (1839-), American journalist and author, served in the Confederate army; was managing editor and later editor-in-chief of Hearth and Home (1871-1874); was literary editor of the New York Evening Post (1875-1881), literary editor and afterwards editor-in-chief of the New York Commercial Advertiser (1884-1889), and editorial writer for The World (New York) from 1889 to 1900.