CREATE TABLE table_10481 ("Date" CLOB, "Track" CLOB, "Race" CLOB, "Dist." CLOB, "Purse  (  US$  ) " CLOB, "Track Surf." CLOB, "Winning horse" CLOB, "Win jockey" CLOB)

What was the Illinois Derby purse?
SELECT "Purse ( US$ )" FROM table_10481 WHERE "Race" = 'illinois derby'
SELECT "Purse ( US$ )" FROM "table_10481" WHERE "Race" = 'illinois derby'