[11] MacAgy worked at the California Palace of the Legion of Honor in San Francisco for 14 years.
Over the span of that time she held "positions ranging from curator to acting director" (Herbert 1998, pp. 31–32).
Throughout her career at the Legion of Honor she established a reputation for her exhibitions that were presented in a new and dramatic style, as well as her focus on the museum's educational outreach.
There she "reinvented the space," especially by her use of new and diverse platforms of display that "included potted plants, beds of gravel and bark, temporary partitions, scrims, theatrical lighting, and pedestals of all shapes and sizes combined in unusual ways" (Herbert 1998, p. 32).
Her exhibitions at the Contemporary Arts Association include Mark Rothko in 1957, "The Trojan Horse: The Art of the Machine" in 1958, "The Common Denominator: Modern Design, 3500 BC- 1958 AD" in 1958, and "Romantic Agony: From Goya to de Kooning" in 1959.