Sharing a joint interest in the period my brother called my attention to the following display.
"National Colours and (above it) a fragment from the Regimental Colour of the 4th American Regiment of Infantry.
These are extremely rare. The Colours (flags) are the heart of an infantry regiment. The US Army has not lost many. These Colours were surrendered to our 41st Foot after the capture of Fort Detroit on 16 August 1812, during the War of 1812."
|National Colour - Detail of Eagle|
|'The Forth Regiment' detail|
You are not allowed to use flash photography in the museum and the lighting around the flags are deliberately keep subdued to protect the habit, hence the poor quality of the images (that's my excuse and I'm sticking to it!).
Due to the low lighting levels I couldn't tell if the Regimental flag was buff, white or yellow, the traditional colours used. Versions of this flag, suitable for 28mm figures, are available from Flags of War - 1812 US Regiment flags.
As far as I'm aware the only other US flags from this period still held in British hands are in the Shropshire Regimental Museum at Shrewbury Castle. These are the flags of the 68th , 85th and the 1st Harford Light Dragoons captured, oddly enough, by the British 85th Light Infantry.