Description Meet history's game changers! This biography series is for kids who loved Who Was? and are ready for the next level . In 1849, Harriet Tubman crossed a very important line--the Mason-Dixon Line. She had escaped slavery! Despite grave risks, she went on to become the most famous conductor on the Underground Railroad, helping hundreds of enslaved people reach freedom. From an early age, Harriet always had deep faith and a strong sense of justice. Find out how she became one of history's greatest trailblazers! Trailblazers is a biography series that celebrates the lives of amazing pioneers, past and present, from all over the world.