CREATE TABLE table_18631 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "First elected" FLOAT, "Result" CLOB, "Candidates" CLOB)

William Fadjo Cravens serves the fourth district of Arkansas.
SELECT "District" FROM table_18631 WHERE "Incumbent" = 'William Fadjo Cravens'
SELECT "District" FROM "table_18631" WHERE "Incumbent" = 'William Fadjo Cravens'