Whistle-stop west

"Nine-year-old Ethan Cooper has managed to keep his family together for a year in a Pennsylvania orphanage. Now he and his siblings are boarding a train headed west. He can't help but worry: Mr. and Mrs. Rush in Nebraska have agreed to adopt all four Cooper children, but what if they change their minds? In the meantime, Ethan and his siblings encounter their first dust storm, explore train cars, and watch friend after friend leave with new parent...