In the Directory of American Military Goods Dealers & Makers 1785-1915, Lamson & Hubbard have the following entry: "Boston. Hats. Listed under 'military goods' in 1900 Boston City Directory. The firm was at 90 and 94 Bedford in 1898 and 92 Bedford & 299 Washington in 1900 - 1901."
This is a militia officer dress cap from the turn of the century ca 1900. These turn up all of the time in great shape due to their specially designed hat cases.