The Box-Car Children - Gertrude Chandler Warner

Four children: Henry, Jess Violet and Bennie. They are living alone in a stranded boxcar. They find items they need from the dump and a stray dog whom they name Watch. Henry earns money by working for a man named Dr. McAllister and his mother, Mrs. McAllister. But, while they are living their daily lives, little do they know that the McAllisters are watching their every move. (Summary by francesb)