The family moved to Los Angeles in 1894 to establish a winter home, and Nelson invested heavily in real estate, forming the basis of the family's interests in Southern California. Nelson Story died on February 9, 1924. Walter was the youngest of the family with two older brothers and a sister. Walter received his early education in the public schools of Bozeman, later attending both public and private schools in Los Angeles. At sixteen years old he entered Shattuck Military Academy at Faribault, Minnesota. He was there until 1902, and graduated from the Eastman Business College at Poughkeepsie, New York in 1903. He returned to Bozeman where got involved with the Commercial National Bank as a bookkeeper and teller for two years, before returning to Los Angeles in 1905. In 1907 he got involved in the real estate business himself with Arthur E. Tandy under the name of Tandy & Story.
The piece of land that Story built the Walter S. Story Building on was purchased by his father in 1895 for $50,000. When Walter was fourteen years old his father presented him with the lot. Walter began the erection of the million dollar building in April 1908 and the building was completed on April 1, 1910. Standing twelve stories high, and with a frontage of 120 feet on Broadway and 150 feet on Sixth Street, it was one of the most modern for its day. After the success and profitability of this venture, Story soon developed a reputation as one of the young financiers of Los Angeles. One other such construction was the multi-million dollar building of the Los Angeles Stock Exchange Building on South Spring Street, completed in 1921.
His military career became equally as impressive as his business career. He began by enlisting in the army as a private. He created what was then Battery A of the California Field Artillery and raised funds to build an armory and stables in Los Angeles. After being discharged from World War I service, in December 1920, Walter was commissioned as Captain of the California National Guard and began devoting his energies toward reorganizing the National Guard in Southern California. In 1921 he was promoted to Major and organized his own military company.
In 1933 he graduated from the U.S. Army War College and was later promoted to the rank of Major General in July 1937. After he completed the General Officers Course in 1940 he assumed command of the 9th Army Corps, Fort Lewis, and entered Federal Service in March 1941, where he assumed command of the 40th Infantry Division, which now composed of the National Guard elements from California, Arizona and Utah. Having served through the ranks from private to Major General, he understood his men well and his division was known for its high morale. He was relieved from command due to protracted illness in September 1941, and retired from active list in July 1942. Among his citations and decorations include Victory Medal (World War I), Service Medal (25 Years), Medal of Merit, American Defense Service Ribbon, and the Order Crown of Italy.
Until his death in 1957, he maintained his office in the Walter P. Story Building and resided at 3405 Laurel Canyon Blvd., North Hollywood. Today, housed in the California State Military Museum is the Walter P. Story Memorial Library and Research Center. This library possesses one of the finest collections of military history writings in the western United States. With over 10,000 volumes and growing rapidly, the library is one of the state's hidden educational and historical treasures.