CREATE TABLE table_73873 ("Episode #" FLOAT, "Airdate" CLOB, "Movie Title and Year" CLOB, "Main Cast" CLOB, "Network TV Run Time" CLOB)

Who was the cast on the 3/23/1963 episode?
SELECT "Main Cast" FROM table_73873 WHERE "Airdate" = '3/23/1963'
SELECT "Main Cast" FROM "table_73873" WHERE "Airdate" = '3/23/1963'