Twelve-year-old Abilene Tucker is the daughter of a drifter who, in the summer of 1936, sends her to stay with an old friend in Manifest, Kansas, where he grew up, and where she hopes to find out some things about his past.

Before John Glenn orbited the earth or Neil Armstrong walked on the moon, a group of dedicated female mathematicians known as "human computers" used pencils, slide rules and adding machines to calculate the numbers that would launch rockets, and astronauts, into space. Among these problem-solvers were a group of exceptionally talented African American women, some of the brightest minds of their generation. Originally relegated to teaching math in...