Close your eyes and picture a classic 19th-century painting of a mother and child: soft pastels, a baby's bath, overwhelming tenderness. The artist most responsible for that enduring image of motherhood was a fiercely independent American expat who rejected marriage and motherhood for herself, and this episode unpacks that phenomenal contradiction. Born into Pennsylvania wealth in 1844, Mary Cassatt enrolled in art school at 15 over her family's objections, endured a curriculum that barred women from studying anatomy, and moved to Paris in 1866 only to find the world's greatest art school would not let her through the door. So she hacked the system: private tutors hired from that same school, and a copyist's permit that turned the Louvre into her classroom, studio, and coffee house in one.

Her road ran through a war that sent her home, a fa ...