today. But just a few decades ago, opportunities for girls were far more limited, not because they weren't capable of playing or didn't want to become doctors or lawyers, but because they weren't allowed to. Then quietly, in 1972, something momentous happened: Congress passed a law called "Title IX," forever changing the lives of American girls.

Hundreds of determined lawmakers, teachers, parents, and athletes carefully plotted to ensure that the law was passed, protected, and enforced. Time and time again, they were pushed back by erce opposition. But as a result of their perseverance, millions of American girls can now play sports. Young women make up half of the nation's medical and law students, and star on the best basketball, soccer, and softball teams in the world. This small law made a huge difference.

From the Sibert Honor-winning author of Six Days in October comes this powerful tale of courage and persistence, the stories of the people who believed that girls could do anything — and were willing to fight to prove it.

Title IX became law when Ms. Blumenthal was a young teen, and for years it represented a possibility that always seemed just out of reach. That's not so today: Most girls she knows play sports, and their opportunities are genuinely endless. Awed by the changes she has seen, Ms. Blumenthal set out to share the story of this untold social revolution. She spent two years scouring archives, academic works, and newspapers, tracking down participants and star athletes to help her reconstruct what happened.

A veteran Wall Street Journal editor and reporter and a die-hard sports fan, Karen Blumenthal is the author of Six Days in October, a 2003 Sibert Honor Book. She lives with her husband and two daughters in Dallas, Texas.