Adelaide Hanscom was born the fourth of 6 children in Empire City, Oregon on November 24, 1876. The family moved to Berkeley, California, in 1881. Adelaide dropped out of school at the age of 15 to pursue art on her own, and by 1892 she was showing her work at the state fair. In 1895 she began studying privately with a local artist, Mrs. Loosely, and in 1897 she hung her first exhibition of paintings at the San Francisco Mechanics Institute. It is presumed that she began studying photography at this time, while also teaching drawing and painting at a variety of Berkeley public schools, as well as at the Mark Hopkins Institute of Art.

In 1902 she opened a studio in San Francisco, focusing on photography. She became an established fine and commercial photographer, and when her studio was destroyed in the 1906 earthquake, she moved to Seattle and opened a studio with Gertrude Willison. She continued working in the Bay Area as well as Seattle. In 1907 she married Gerald Leeson, with whom she would have two children. She continued to study photography until Gerald's death in WWI in 1918.

She continued to teach drawing and painting, and exhibited throughout United States as well as abroad, until two years before her untimely death after being hit by a car on November 19, 1931 in Los Angeles.

Exhibitions: San Francisco Mechanics Institute, 1897-1899; Starr Kings Fraternity, Oakland, 1902; Third Photographic Salon, S.F., 1903; First and Second American Photographic Salon, 1904 -1905; Women's Photography, Connecticut, 1906; 14th Annual London Photographic Salon, 1906, among others; Photo-Secession Exhibit, 1907, among others.

Awards: First prize, S.F. Bulletin, figurative, (1904); first place, Alaska-Yukon-Pacific-Expos. medal design (1907); among others. Published (essays and reproductions): Camera Craft,1902; Photographs of the Year, 1904; Sunset, 1904; Photographic Times, 1905; published The Rubaiyat of Omar Khayyam, 1905; Photographic Monthly, 1906; publishes the "Rubaiyat" series, 1910.