user: Question: What was the Illinois Derby purse?
Columns: ['Date', 'Track', 'Race', 'Dist.', 'Purse ( US$ )', 'Track Surf.', 'Winning horse', 'Win jockey']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['January 13', 'Fair Grounds Race Course', 'LeComte Stakes', '1 Mile', '$98,000', 'Dirt', 'Hard Spun', 'M. Pino']
SQL:

assistant: SELECT "Purse ( US$ )" FROM "Table" WHERE "Race" = 'Illinois Derby';