CREATE TABLE table_204_823 (id DECIMAL, "dates" TEXT, "location" TEXT, "attendance" TEXT, "official guests" TEXT, "notes" TEXT)

what was the first year the event was held at the pick congress hotel in chicago ?
SELECT MIN("dates") FROM table_204_823 WHERE "location" = 'chicago'
SELECT MIN("dates") FROM "table_204_823" WHERE "location" = 'chicago'