 He became known as a speaker, a frequent contributor to periodicals, president of the Society of American Authors, and, after 1885, of the New York Genealogical and Biographical Society.He edited Fitz-Greene Halleck's "Poems" (1868) and wrote his biography, published in 1869; and in 1876 his anthology "Poets & Poetry of Scotland" in four volumes .He edited "A Memorial History of the City of New York" (four volumes, 1892–93); "Appletons' Cyclopædia of American Biography" (six volumes, 1887–89, with John Fiske; volume vii, 1900); "The Great Commanders Series" (eighteen volumes, completed 1913); and .