The poem was also published in the American Quarterly Review, Vol. XIII (Feb. 1841), p. 238. AQR gives the same date, 1820, as CRM Sewell's journal, and unlike Salisbury, who give a date of 1819. AQR also implies the state is not in the original by enclosing it in parentheses, like the journal, and also unlike Salisbury.
The two Henry Sewalls referred to in the poem are no doubt first cousins Henry Sewall (1615-1700) of Massachusetts and Henry Sewell (ca. 1625-by 1665) of Maryland. The first came to Massachusetts, for the third (or fourth) and last time, in 1659 and his family followed in 1661 shortly after the coronation of Charles II. The second also came to Maryland about 1661.
Has anyone found any additional evidence that either Henry actually fought in the English Civil War?