With a valid driver's license from your own country, it is good for one year after your arrival in the United States though states may have specific laws that will affect you.

Generally, a person with a valid foreign / international driver's license in their possession may drive a private, non-commercial motor vehicle in the State of Texas for up to one year from date of entry into the United States. The state lists the countries with which the US and thus the state of TX have reciprocal agreements with.

So it is normally your valid foreign license that allows you to drive in the US which a visitor or tourist. While an international driving permit (IDP) or international driving license (IDL) is helpful because it translates your foreign license into English.

If you have a driver license from your home country, it is usually not advisable to use it alone, even with the reciprocity. You also need to carry an International Driving License (IDL) or Permit (IDP). An IDL is a translation booklet which enables officials in other countries to comprehend your actual state or nationally issued driver license.

The IDL indicates that you have a valid driver license and that you are allowed to drive in the US. The IDP is basically the same type of document. An IDL or IDP by itself does not constitute a legitimate permit to drive; you must hold a valid driver’s license from your home country in conjunction with this international license or permit.

If your home country does not have a reciprocity agreement with the U.S. or you are planning to stay in the U.S. for more than one year, you will have to apply for a Texas driver license to legitimately drive in this State. You can get more specific information about your situation from the Texas Department of Public Safety (DPS) and by reading the Subchapter E, of Chapter 15, Part 1 of Title 37 of the TX Administrative Code.