CREATE TABLE "ships" (
  "ship" text,
  "builder" text,
  "namesake" text,
  "renamed" text,
  "laid_down" real,
  "launched" text,
  "commissioned_or_completed" text
);

Question: When was the ship launched when the commissioned or completed(*) is 6 june 1864?
SQL: SELECT "launched" FROM "ships" WHERE "commissioned_or_completed"='6 June 1864';

Question: When was the ship tecumseh launched?
SQL: SELECT "launched" FROM "ships" WHERE "ship"='Tecumseh';

Question: What is the namesake of the ship that was commissioned or completed(*) 16 april 1864?
SQL: SELECT "namesake" FROM "ships" WHERE "commissioned_or_completed"='16 April 1864';

Question: What is the minimum laid down?
SQL: SELECT MIN("laid_down") FROM "ships";