Goodnight Mister Tom by Michelle Magorian
At the start of WWII, families in London sent their kids to the English countryside as evacuees to keep their children safe. William is one of the children that was placed in small country town of Little Weirwold with Tom and his dog Sammy. Will is timid and small, having been physically and verbally abused by his mom. Tom is a widower who lost both his wife and son many years ago. Tom helps strengthen Will with food and love and helps him learn to read and write. At the same time, Will helps Tom become less of a recluse and enjoy life a bit more.
This book is heartbreaking. Will is such an innocent kid but is so traumatized by his mother's treatment that it's impossible not to feel deeply saddened by his condition. Magorian did a fantastic job not only of showing how a child can overcome abuse but how a man can break out of his depression and learn to love a kid that just happened in to his life.
First Line: "'Yes,' said Tom bluntly, on opening the front door."