As an undergraduate, he waited tables and worked at the night copy desk of the Grand Forks Herald, and was active in the school's literary and dramatic societies. He became the principal of a high school in Minnewaukan, North Dakota, also teaching English there, but was fired in 1913 for making pacifist statements to his students. He became a high school English teacher in San Francisco: after three years he became chairman of the English department at Whittier College in 1917. He was fired after a year for public statements supporting Arthur Camp, a jailed student seeking status as a conscientious objector.Anderson moved to Palo Alto to write for the San Francisco Evening Bulletin, but was fired for writing an editorial stating that it would be impossible for Germany to pay off its war debt. So he moved to San Francisco to write for the San Francisco Chronicle, but was fired after contracting the Spanish Flu and missing work. Alvin Johnson hired Anderson to move to New York City and write about politics for The New Republic in 1918, but he was fired for winning an argument with Editor-in-Chief Herbert David Croly.
Anderson found work atThe New York Globe, and the New York World. In 1921, he founded The Measure: A Journal of Poetry, a magazine devoted to verse.
He became a playwright only after careers as a schoolteacher and a journalist. His first produced play, The White Desert (1923), a study of the tragic consequences of marital jealousy, was a failure, but success followed when he collaborated with Laurence Stallings on the war drama What Price Glory? (1924). After several other less satisfactory collaborations with Stallings, he again found acclaim with his picture of white‐collar married life, Saturday's Children (1927). Anderson's first attempt to dramatize the Sacco‐Vanzetti case, Gods of the Lightning (1928), written with Harold Hickerson, won little attention; but later in the same season his examination of a mercurial, unstable flapper, Gypsy (1929), won some high praise. He turned to blank‐verse drama for his recounting of the Elizabeth‐Essex story, Elizabeth the Queen (1930), and its success prompted him to write many of his subsequent dramas in similar blank verse, making him the only major 20th‐century American playwright to do so. His subsequent highly lauded plays include Night Over Taos (1932), about the Spanish resistance to American advances in early 19th‐century New Mexico; the political satire Both Your Houses (1933); Mary of Scotland (1933), centering on Mary Stuart; Valley Forge (1934), dealing with Washington's struggles in the Revolutionary War; Winterset (1935), another play based on Sacco and Vanzetti and the first work to win the New York Drama Critics Circle Award; Wingless Victory (1936), a story of a doomed interracial marriage; and the fantasy High Tor (1937). His 1937 verse play about the Mayerling incident, The Masque of Kings, failed, but was followed by The Star Wagon (1937), a fantasy about a couple who return to their youth to reconsider their lives. More verse plays followed: Key Largo (1939), dealing with the Spanish Civil War; Journey to Jerusalem (1940), a story of the young Jesus; and Candle in the Wind (1941), an antiwar play. The Eve of St. Mark (1942) depicted a family farm during the war, Storm Operation (1944) centered on the North African campaign, and Truckline Cafe (1946) told of an ex‐soldier's search for his unfaithful, shamed wife. Joan of Lorraine (1946) succeeded largely on the appeal of Ingrid Bergman in the title role. He used historical personages Anne Boleyn in Anne of the Thousand Days (1948) and Socrates in Barefoot in Athens (1951), and adapted William March's novel about a vicious child, The Bad Seed (1954). Anderson also wrote the book and lyrics for two Kurt Weill musicals: Knickerbocker Holiday (1938), which included “September Song,” and Lost in the Stars (1949). His frustration with producers led him to cofound the Playwrights' Company in 1938, and he often railed against the drama critics, once calling them “a sort of Jukes family of journalism” and adding, “It is an insult to our theatre that there should be so many incompetents and irresponsibles among them.”