William Sumner Appleton, Jr. (May 29, 1874–1947) was Founder of the Society for the Preservation of New England Antiquities (SPNEA) in 1910. He was the chief force behind much of the preservation of historic homes in the New England area.
Appleton, who had a degree from Harvard and was economically comfortable, worked tirelessly to promote preservation of buildings from the 17th, 18th, and early 19th centuries. He focused on buildings that were aesthetically pleasing, had historic significance, and could be independently supported. His method of preservation focused on cautious, deliberate restoration only when experts were involved and restorations were reversible. When he died in 1947, the SPNEA had grown tremendously and remains a strong and active organization today. Renamed Historic New England, the organization owns thirty-six historic properties.
Appleton was born on May 29, 1874 in Boston to William Sumner Appleton (1840–1903) and Edith Stuart (d.1892). As a boy he lived at 39 Beacon Street (also known as the Nathan Appleton Residence).
He was educated at Hopkinson's School for Boys, Boston, and graduated from Harvard College in 1896.
Around 1916 Appleton lived on Spruce Street in Boston.
Appleton died on November 24, 1947, in Lawrence, Mass.