user: Question: What is the date successor seated where Massachusetts 2nd is the district?
Columns: ['District', 'Vacator', 'Reason for change', 'Successor', 'Date successor seated']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['North Carolina 7th', 'John Culpepper (F)', 'Seat declared vacant January 2, 1808', 'John Culpepper (F)', 'Seated February 23, 1808']
SQL:

assistant: SELECT "Date successor seated" FROM "Table" WHERE "District" = 'Massachusetts 2nd';