Fayez Sarofim & Co. US Men's Clay Court Championship, Houston
In 1970-1989 the tournament was a part of the Grand Prix Circuit. From 1990 to 1999 the tournament was a part of World Series (now - ATP World 250 series). From 2000 to 2008 tennis tournament in Houston was a part of International Series (now - ATP World 250 series). Since 2009, the tournament has been a part of the ATP World 250 series.