Agness Underwood was a Los Angeles newspaper woman for forty-two years. She started her long and successful career in the newspaper business as a switchboard operator in 1926, when she was hired on temporarily by the Los Angeles Record. Her first newspaper experiences began on a part-time basis under the wing of Gertrude Price, helping with the Cynthia Gray Christmas Basket project sponsored by the Record. From time to time, Underwood was also given assignments covering junior women's clubs events. For the next four years Underwood worked on a more or less part-time reporter status.

In 1931, events and assignments increased, which quickly showed her talents. Underwood's big chance came on May 20, 1931, when, "Los Angeles officialdom was shaken by the shooting and killing of Charles H. Crawford and Herbert F. Spencer by an unidentified assailant in Crawford's office on Sunset Boulevard, Hollywood." She began "grubbing" and came up with an exclusive interview with a suspect's parents, providing her first city side by line: "Mrs. Clark Says Son is Innocent." A second interview covering the murders was with the wife of slain newspaperman Herb Spencer. Underwood's crime reporting career had begun.

In 1935, Underwood moved over to William Randolph Hearst's Los Angeles Herald and Express and remained with the paper until her retirement in 1968.

During the 1930s and 1940s she was one of the city's best-known court and police reporters. She became well known for her sharp news sense in compiling a long record of scoops and exposés while covering many famous crimes and Hollywood related stories. Headlines for Underwood's reporting included: "Find Thelma Todd, Film Star, Dead in Mystery" (December 16, 1935); " Missing Inglewood Tots Found Murdered" (June 28, 1937); "Girl in Dance Murder Probe Tells Downward Path" (November 23, 1944). Underwood also sat front row for the trials of Charlie Chaplin and Errol Flynn.

In 1947, she became city editor of the Herald Express, a post she held for seventeen and a half years. During that time she was the only woman city editor of a major American metropolitan newspaper. No man had ever held the job more than four years, and during her editorship she helped push the Herald's circulation up over 700,000, which made it the largest afternoon daily in the west at that time. With a sawed-off baseball bat on her desk and a starter pistol in her drawer, she ran a staff of hard-nosed reporters and photographers who endeared her with the name "Aggie." Relationships were based on concern, respect and honest affection. Underwood's record as a woman in the hectic world of big city journalism was unparalleled, and it made her a legend in her time.

Underwood retired from the Los Angeles Herald Examiner in 1968, eventually moving to Greeley, Colorado to live with family. She passed away in 1984. Agness was survived by two children and five grandchildren.