user: Question: What was the successor for Vacant Alabama 3rd?
Columns: ['District', 'Vacator', 'Reason for change', 'Successor', 'Date successor seated']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['New Mexico Territory At-large', 'Vacant', 'Vacancy in term', 'Charles P. Clever (D)', 'September 2, 1867']
SQL:

assistant: SELECT "Successor" FROM "Table" WHERE "Vacator" = 'Vacant' AND "District" = 'Alabama 3rd';