I'm sure you know a unit of Sea Fencibles was stationed in Rockport, Massachusetts. Their Historical Society may have information. I know from childhood visits that a building that was their quarters is marked by a plaque.
"The Historical Register and Dictionary of the United States Army" by Francis Heitman (GPO, 1903) Vol. I, has a brief organizational note about the Fencibles on p. 143. You may be able to track down records and reports from here. Volume II has a chronologic list of battles that may list any actions they were in. This work is available in most public libraries.
James B. Ronan II
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