Statistics for occurrence #1 of “Ship Island” in year 1862, month February, day 21 of Rebellion Record: a Diary of American Events, Diary from December 17, 1860 - April 30, 1864:

...ling, Va., to join Gen. Rosecrans. The Massachusetts Thirty-first regiment, and five companies of the Thirteenth Maine regiment, sailed to-day from Boston, Mass., in the steamer Mississippi for Ship Island .
...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
Ship Island (Mississippi, United States) 953 41 73 1 0 user votes
Ship Island (Alaska, United States) 0 0 0 0 0 user votes
Ship Island (Alaska, United States) 0 0 0 0 0 user votes
Ship Island (Idaho, United States) 0 0 0 0 0 user votes
Ship Island (Maine, United States) 0 0 0 0 0 user votes
Ship Island (Maine, United States) 0 0 0 0 0 user votes
Ship Island (Maine, United States) 0 0 0 0 0 user votes
Ship Island (Mississippi, United States) 0 0 0 0 0 user votes
Ship Island (New Hampshire, United States) 0 0 0 0 0 user votes
Ship Island (New York, United States) 0 0 0 0 0 user votes
Ship Island (Ohio, United States) 0 0 0 0 0 user votes

† This entity has been selected by the automated classifier as the most likely match in this context. It may or may not be the correct match.