The tournament is a part of the ATP world tour 250 series since 2009 .
The U.S. Mens Clay Court Championship is the only clay court ATP tournament remaining in the U.S. and an annual ATP tennis tournament that started in the year 1910 .
The tournament is a part of the ATP world tour 250 series since 2009 .
The U.S. Mens Clay Court Championship is the only clay court ATP tournament remaining in the U.S. and an annual ATP tennis tournament that started in the year 1910 .