“Horses lend themselves to stories,” writes Sarah Maslin Nir. And Maslin Nir knows stories. She has crisscrossed the globe as a staff reporter for The New York Times. And when she's on assignment, if there's a sliver of free time, she checks out a place’s horses. Her new book is "Horse Crazy: The Story of a Woman and a World in Love with an Animal." It includes a chapter on how Black cowboys have been largely left out of the story of the American West.