Delaware saw a record $16.8m placed in sports bets in September.
The amount wagered more than doubled from August’s $7.7m, while monthly revenue was $3.6m, up from about $700,000 in August.
Delaware Park was the lead taker of the three regulated venues, with a total of $11.6m in bets placed, making up 69% of all bets in the state.
Dover Downs saw bets of $3.3m and Harrington Raceway received $2m.
Delaware became the first state to legalise sports betting in the wake of the Supreme Court’s ruling on the Professional and Amateur Sports Protection Act.
The regulated market went live on 5 June, with $322,000 in wagers placed on the first day.
Players can also make legal sports wagers in Nevada, New Jersey, Mississippi and West Virginia.