Following a short internship at the Fogg Art Museum in 1928, she was hired as a research assistant for associate director Paul J. Sachs, where she remained until 1937.

From 1937 to 1947, she was promoted to new a position titled "Keeper of Drawings," since women were not allowed to be named curators.

She also became acting director of the Timken Museum of Art in San Diego, California, for a period.

[3] She was honored by the Harvard Art Museums in 1994 when the Agnes Mongan Center for the Study of Prints, Drawings, and Photographs opened at the Fogg, which was designed by Samuel Anderson Architects.

[4] After her retirement in 1975, she remained as an emeritus curator for the Fogg and continued to produce exhibitions and related catalogues.