CREATE TABLE "table1_225199_4" (
  "district" text,
  "vacator" text,
  "reason_for_change" text,
  "successor" text,
  "date_successor_seated" text
);

Question: What is every date successor seated for the Virginia 11th District?
SQL: SELECT "date_successor_seated" FROM "table1_225199_4" WHERE "district"='Virginia 11th';