The flag is assigned to sailings during 1830–1839.
Ploughboy operated from Nantucket in 1821–1843, then was sold to New Bedford. Owners included Philip Folger, Philip H. Folger, Philip C. Folger and Valentine Hussey. Philip H. Folger and Val. Hussey & Bro. acted as agents in the later period.
Keep the explicit scope label independent; no alias or company identity is inferred.