Lucy Hobbs, later Lucy Hobbs Taylor, pursued a career in dentistry before that was recognized as an acceptable vocation for a woman. She got told no a lot, but became a well-respected leader in the field.
Research:

Robert Moses and the Shaping of New York, Part 2
42:12

Robert Moses and the Shaping of New York, Part 1
41:59

SYMHC Classics: Eradication of Smallpox
43:25