Googled up the following.
MikeT

The maple fife came to the early New World as a military instrument with European soldiers and a folk instrument with settlers. In 18th century Europe and her American colonies, one fifer and one drummer were assigned to each company regiment. It was of utmost importance that the company fifer and drummer know their signal calls and play them perfectly as lives depended on the fife and drum calling out orders on the battlefield and in the camp.

The names tin whistle and penny whistle date from when the instrument was first mass produced in tinned sheet metal. Early mass production of the metal itself occurred in Wales, in the United Kingdom, and the best known (most successful) early producers of tin whistles is Robert Clarke (? - 1882) who lived and worked in the UK territory of England. Norman Dannat boasted in “The Penny Whistle” (The Clarke Tinwhistle Co c1993) that Robert Clarke’s whistles ‘produced a unique sound which, though attempts have been made to copy it, no-one has ever improved’. In his tutor “Timber” (ISBN 185700322) Fintan Vallely calls the whistle’s fingering system the ‘simple’ system. It is also that to which the side-blown six-hole flute responds and was of course well known before Robert Clarke began producing his tin whistles circa 1843. Whistles may or may not be tuneable.The whistle is in a single key, usually D for Celtic music, and C for American folk music, though whistles are available in all the major keys.