I came across a web site that enables you to search a large number of historic New York State newspapers simultaneously. It can be a bit tricky since the old papers have apparently been scanned using optical character recognition (OCR) technology, which is pretty impressive but not perfect. Therefore, your search terms may not match an article that it should if the OCR misinterpreted the print. Here’s what I’ve found so far focusing on William H. Marshall, Maria Peterson (his second wife) and Thomas J. Marshall (his father):
William Halsey obit mention T J Marshall 25 Nov 1852 – A notice that the four year old son of William Marshall’s sister Evelina Halsey died of croup. Friends of the deceased’s grandfather, Thomas J. Marshall, are invited to attend the funeral.
T J Marshall death notice 11 Feb 1869 – Thomas J. Marshall appears to have been visiting his son William in Auburn, NY, and died while attending a Sunday church service.
T J Marshall funeral notice NY Herald 10 Feb 1869 – A short but interesting obituary. Mentions his previous employment as the clerk of the Blackwell Island Almshouse and that he was a member of the Free and Accepted Masons. Since the funeral was held in New York, I assume he was still residing there rather than in Fleming with his son William (whom he appears to have been visiting at the time of his death). Friends and relatives are invited to attend the funeral from the residence of his son in law (not clear who that is or which of Thomas’s four daughters he’s married to) at 61 St and First Avenue.