Walker was one of the first and most prolific female mountaineers of the 19th century. Over the course of her 21-year career in the Alps, starting in 1858, Walker undertook 98 expeditions, including 28 successful attempts on 4,000-meter peaks. She holds first female ascents on 16 summits, including Monte Rosa, the Strahlhorn, and the Grand Combin, and a first ascent for either sex on the Balmhorn, which she completed in 1864.

Wilma Rudolph was known at one point as the world’s fastest woman and was among the most successful and famous athletes of her era. At six feet tall she was graceful and lithe; she was also thoughtful and humble, and quickly won over the press, which often touted her as a symbol of the merits of democracy and American perseverance during the Cold War. While her underdog story of athletic victory has been celebrated in the media and popular culture, her lifelong struggle against racism and sexism, and her powerful role as a champion for civil rights and gender parity, are less well known.

Of her half-dozen siblings, Aimée was the wild child, an unapologetic rule breaker and inspiration to nonconformists everywhere. While other women were just starting to venture into European capitals, she was plunging deep into jungles, sailing across oceans, and racing on horseback with locals on Hawaiian beaches. Crocker spurned racist, colonialist, and sexist ideologies; brazenly crossed class boundaries; and embraced non-Christian religions—to the scandal of American high society.

Blackjack was barely five feet tall and 100 pounds and lacked any wilderness skills. Nonetheless, she taught herself to hunt and trap, picked roots, hauled wood, made her own clothing, dodged hungry polar bears, and cared for Knight.

Gertrude Ederle had surprised competitors and spectators right from the start of her storied career as one of the 20th century’s best athletes, male or female. In her first major race, the Day Cup, a 3.5-mile international women’s race between Manhattan Beach and Brighton Beach, she entered as a complete unknown and beat the reigning American and European champions. She was 15.