Eliza Marquess graduated from the Wadleigh High School for Girls, the first public girls’ school in New York City. She then entered Barnard College and in 1917 received her BA in French. After graduation, Marquess became an editorial assistant at the publishing house of Longman's Green & Co.
Marquess started at NYPL in 1918 as a substitute, and later did both children’s work and school and reference work. She entered the NYPL Library School in 1926, but it does not appear that she finished the studies required to receive a certificate.
In 1933 she was promoted to Superintendent of the Book Order Office (BOO) and served there until 1944. A 1938 profile in the New York Times called Marquess one of the largest book buyers in the world and noted that she had purchased one million books for NYPL in her first five years in BOO--despite the fact that New York City had cut the allocation for book purchases in 1933 due to the Depression.
In her book, An Ample Field (Chicago: ALA, 1950), Amelia Munson (a colleague at NYPL) quoted Eliza Marquess’ definition of book selection as “‘the practice of supplying people with the books they want, and of setting before them the books they don’t know that they want.’”
In 1944, Marquess left BOO and returned to branch work as head of the Harlem Branch. She retired from NYPL in 1962.