The estate is part of the Hunnewell Estates Historic District, which includes the estates of many of his descendants. During the first part of the 20th century there were 20 contiguous for him and his family in Wellesley. Among other miscellaneous activities, Hunnewell owned the home in which Horatio Alger's father lived until his death, now called the Horatio Alger House in Natick, Massachusetts. Oliver Bacon had built this house about 1824, and sold it in 1869 to Hunnewell. In 1909, Hunnewell deeded the property to the First Unitarian Church of South Natick as a parsonage.