This information comes from the National Archives Record Group 74, Records of the Bureau of Ordnance, US Navy. The particular entry I got this from contains lists of miscellaneous guns that were at the Philadelphia Navy Yard in 1870's. Many of the strange, nonstandard guns listed were captured Confederate items, both those made or modified in the South, or those which were imported by the Confederacy. It is clear to me from the context that all eleven of the rifled howitzers listed here were captured Confederate weapons.
Notice there are two interesting entries together in the middle of the page:
Five wrought iron Howitzers-rifled-cal. 2.9 in.-219 lbs. each-(marked) "Fawcett, Preston, &Co., Liverpool"
Six Cast Iron -2.9 in. -rifled Mountain Howitzers-269 lbs. each
Bookmarks