H. Marshall Gardiner (1884-1942) was a photographer noted for his hand colored photographs of Bermuda, Florida, and Nantucket, some of which were also made into postcards.
This is a black and white divided back postcard of the Tristram Coffin Homestead landmark marker. Tristram Coffin was one of the founding families and first magistrate of Nantucket. The photo was probably made late in his career, after his second marriage to Bertha Coffin Chase, who was a decedent of Tristram. It appears to be one his rarer postcards, perhaps because fewer were produced because of its atypical subject.
The postcard is not a true photograph, but some form of printing process, but the detail is good. It has a light water stain blotch on the front top right, but is in otherwise in very good unused condition. It will be shipped via first class mail letter with card stock.