user: ### NOW ANSWER:
Question: Why did the change happen in the state where the formal installation happen on February 14, 1859?
Columns: ['State (class)', 'Vacator', 'Reason for change', 'Successor', 'Date of successors formal installation']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Tennessee (1)', 'Vacant', 'Vacancy in term', 'Andrew Johnson ( D )', 'October 8, 1857']
SQL:

assistant: SELECT "Reason for change" FROM "Table" WHERE "Date of successors formal installation" = 'February 14, 1859';