what was the reason Richard K. Meade ( d ) became a successor?
CREATE TABLE "table1_228439_4" (
  "district" text,
  "vacator" text,
  "reason_for_change" text,
  "successor" text,
  "date_successor_seated" text
);
SELECT "reason_for_change" FROM "table1_228439_4" WHERE "successor"='Richard K. Meade ( D )';