CREATE TABLE table_18555 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Result" TEXT, "Candidates" TEXT)

What party does the incumbent from the Ohio 7 district belong to?
SELECT "Party" FROM table_18555 WHERE "District" = 'Ohio 7'
SELECT "Party" FROM "table_18555" WHERE "District" = 'Ohio 7'