This miter cap, measuring 10″ x 8.25″ x 8.25″ is made of leather with a painted front. Specifically, this was worn by the Newport Light Infantry in Newport, Rhode Island. The unit had 100 members and no longer existed once the British occupied Newport in 1776. For source and more details, click here.
Image from: http://amhistory.si.edu/militaryhistory/collection/object.asp?id=342&printable=1