Military records are a typical example.
However, because of the arrangement of these records, you cannot write to the Public Record Office, Ruskin Avenue, Kew, Richmond, Surrey TW9 4DU, England, and request a search for your William Winterbotham. You will have to make the trip to England or hire a researcher there to do the work for you. If your ancestor died in service, completed a limited non-qualifying period of service, purchased his discharge, negotiated a free discharge or deserted, you will not find anything about him in these records. British army records start in 1760, and the WO97 records are divided into five periods by dates, with each group arranged differently, meaning that the researcher needs to know some of the peculiarities of this filing system in order to be successful. However, there now is a computerized alphabetical surname index.