user: Question: Who was everyone first elected when incumbent was John J. Hemphill?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['South Carolina 1', 'Samuel Dibble', 'Democratic', 1882.0, 'Re-elected', 'Samuel Dibble (D) 99.9% Others 0.1%']
SQL:

assistant: SELECT "First elected" FROM "Table" WHERE "Incumbent" = 'John J. Hemphill';