user: Question: Who was the incumbent in the district that first elected someone in 1807?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Virginia 1', 'John G. Jackson', 'Democratic-Republican', '1803', 'Re-elected', 'John G. Jackson (DR) 60.3% Noah Linsey (F) 29.7%']
SQL:

assistant: SELECT "Incumbent" FROM "Table" WHERE "First elected" = '1807';