Hollywood producer Hopwood DePree had been told as a boy that an ancestor—who he was named for—had left his family’s English castle in the 1700s to come to America. One night after some wine and a visit to Ancestry.com, Hopwood discovered a photograph of a magnificent English estate with a familiar name: Hopwood Hall, a 60-room, 600-year-old grand manor on 5,000 acres. And with that, Hopwood DePree’s life took an almost fairytale turn. Hopwood...