She is best known for her book Citizen 13660, a collection of 198 drawings and accompanying text chronicling her experiences in Japanese American internment camps during World War II.

Living in a converted horse stall furnished with army cots, they were forced to adjust to the twice-daily roll calls, curfews, and the lack of privacy.

[13] When Fortune magazine learned of her talent, the firm hired her as an illustrator, an arrangement that allowed her to leave the camp after a two-year confinement[6] and relocate to New York.

[10] The title comes from the number assigned to her family unit; the book contains almost two hundred of her pen and ink sketches accompanied by explanatory text.

[18] Okubo's simplistic line drawings and neutral narration provide the reader with a unique perspective on the historical record of the internment.

[14] The Japanese American National Museum in Los Angeles, California, put on an exhibit celebrating the 75th anniversary publishing of Citizen 13660 in 2021.

[4] In 1948, designer Henry Dreyfuss commissioned Okubo to create a large Mediterranean map mural for the main foyer of a new fleet of ships called "4 Aces" for American Export Lines,[21] and her work was later pictured in a Fortune magazine article, Modern Art Goes to Sea.

[4] Following her death in 2001, Okubo's various artworks and papers were transferred to Riverside Community College District, a primary beneficiary of the estate, for preservation of the collection.

[26] The play, interwoven with reminiscences about Okubo's later life as a New York artist, portrays her experiences in the camps of Tanforan and Topaz and shares her artwork and aesthetic principles with the audience.

[7] On February 22, 2006, Riverside Community College honored the memory of its noted alumna when it announced that a street on the campus had been renamed Miné Okubo Avenue.