Question: What party did Robert P. Letcher represent?
SQL: SELECT "Party" FROM "1-2668264-8" WHERE "Incumbent" = 'Robert P. Letcher';

Question: What district(s) did Henry Clay represent?
SQL: SELECT "District" FROM "1-2668264-8" WHERE "Incumbent" = 'Henry Clay';

Question: Who were the candidates for election that had a result of a Retired Jacksonian gain?
SQL: SELECT "Candidates" FROM "1-2668264-8" WHERE "Result" = 'Retired Jacksonian gain';