Houston is not a country and thus does not have its own country code. The country code for the United States, Canada, and 18 assorted islands in or near the Caribbean, is +1. The area codes for Houston are +1 713, +1 281, +1 832, and, beginning in 2014, +1 346.
(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)
Believe it or not, Dallas is not a country unto itself. Not even Texas is a country.
The telephone country code for the United States is +1.
Texas is in country code +1, along with the rest of the US.
Texas
Mexico is the only country that borders Texas.
The zip code for Stinett, Texas is 79083.
Huntsville, Texas, is in area code 936.
The ZIP code for Sealy, Texas is 77474.
The zip code for Texarkana Texas is 75501
Arlington, Texas, is mostly in area code 817 and overlay code 682.
The zip code for Westlake in Texas is: 76262
The cast of Code of Texas Storm - 1921 includes: Texas Guinan as Texas Storm
There is the Texas Hill Country which is located in Central Texas.
A good place to find the Texas Country Reporter is in Waxahachie, Texas, at the Texas Country Reporter Festival. You also can find the Texas Country Reporter on the events in many cities in texas like Houston or Beaumont.
Texas is a state of the United States of America. It is not itself a country, and there is no country within the state. There is a country that shares a border with Texas, and that related question is linked below.