Table: congressional_elections_3
Columns: district
incumbent
party
first_elected
result
candidates

Question: Who were the incumbent(s) in the election featuring  john murray (dr) 50.4% george denison (dr) 49.6% with a result of a retired democratic-republican hold?
SQL: SELECT "incumbent" FROM congressional_elections_3 WHERE "candidates" = 'John Murray (DR) 50.4% George Denison (DR) 49.6%' AND "result" = 'Retired Democratic-Republican hold'

Question: Who were the incumbent(s) when the result was a retired democratic-republican hold and the first elected representative was in 1816>
SQL: SELECT "incumbent" FROM congressional_elections_3 WHERE "result" = 'Retired Democratic-Republican hold' AND "first_elected" = '1816'

Question: Who were the candidates in the election where william wilson was the incumbent?
SQL: SELECT "candidates" FROM congressional_elections_3 WHERE "incumbent" = 'William Wilson'