user: Question: In the district Wisconsin 2nd, what was the reason for change?
Columns: ['District', 'Vacator', 'Reason for change', 'Successor', 'Date successor seated']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Wisconsin 2nd', 'Vacant', 'Robert K. Henry died during previous Congress', 'Glenn R. Davis (R)', 'Seated April 22, 1947']
SQL:

assistant: SELECT "Reason for change" FROM "Table" WHERE "District" = 'Wisconsin 2nd';