Lillian Wald was born in 1867 in Cincinnati, Ohio. Her father, Max Wald, moved his optical goods dealership to Dayton and then to Rochester in search of better opportunities and Wald grew up in upstate New York. Initially trained as a nurse, she left nursing after a year to become a doctor. In the course of her medical training, she became intimately aware of the deplorable health conditions on Manhattan's Lower East Side and she made it her mission to bring public health services to impoverished neighborhoods. In 1895 she founded the Nurses Settlement at 265 Henry Street.

At Henry Street, Wald pioneered the field of public health nursing, working in the neighborhood and treating patients regardless of their ability to pay. Over time, Wald broadened her activities at Henry Street, seeking to attack the root causes of poor health. Similar to Jane Addams' Hull House in Chicago, the Henry Street Settlement hosted social and cultural events, advocated for educational opportunities and expanded green space in the neighborhood, and instituted programs to mitigate against poverty and disease.

Wald's formal career as a social reformer lasted until 1933 when poor health forced her to resign from the board of the Henry Street Settlement. In her retirement, she continued to advocate for her causes, including bringing awareness to the rising tide of antisemitism in Europe. She died in 1940 after a long illness.