By Gertrude Chandler Warner. Children this age relish fantasies of living on their own—hence the popularity of movies such as Home Alone and books such as Where the Lilies Grow. In the first book of The Boxcar Children series, four orphans take shelter in an abandoned train boxcar and turn it into their home. Readers enjoy the themes of self-reliance and mutual caring. A set of the first four books in the lengthy Boxcar series will not only entertain children, but set their imagination roving.