Julia Davis was born in Clarksburg, West Virginia to a prominent family. After her mother Julia McDonald Davis died from childbed fever, young Julia was raised mostly by her grandparents. Her father John W. Davis was a lawyer and partner in the New York-based firm Davis Polk. He served as U.S. Ambassador to Great Britain just after World War I and later ran for president. She attended Wellesley College for two years and then transferred to Barnard College, where she graduated in 1922. The following year, she married William McMillan Adams and began writing books for young people. She made her publishing debut with Sword of the Vikings
in 1927. During her career, she produced more than 20 other books, primarily history and fiction, including the Shenandoah volume for the landmark Rivers of America series. She also wrote two volumes of memoirs, Legacy of Love (1961) and The Embassy Girls (1992), and two novels under the pseudonym F. Draco.
She worked for a year as a reporter for The Associated Press. After divorcing her first husband, she married again twice, and cared for stepchildren and other children who needed homes. She was an agent for the State Charities Aid Association in 1933-1938, and was active in charitable organizations in New York.