There was a Howitzer and Rocket Battalion in the US Army at the time.
They were armed with mountain howitzers and Hale rockets. My references indicate the battalion did not go into action
until Vera Cruz. Maybe Old Rough and Ready had some rockets at Monterey.
Although the rockets were launched from portable troughs they were of 2 inch and 3 inch caliber. Perhaps the Mexicans were confused about the launcher.
James B. Ronan II
To Join the Company of Military Historians click here