Claim: Houston economy has energy as a base.

Houston -LRB- -LSB- ˈhjuːstən -RSB- -RRB- is the most populous city in the state of Texas and the fourth-most populous city in the United States . With a census-estimated 2014 population of 2.239 million within an area of 667 sqmi , it is also the largest city in the southern United States and the seat of Harris County . Located in Southeast Texas near the Gulf of Mexico , it is the principal city of the Greater Houston metro area , which is the fifth-most populated MSA in the United States .   Houston was founded on August 28 , 1836 , near the banks of Buffalo Bayou -LRB- now known as Allen 's Landing -RRB- and incorporated as a city on June 5 , 1837 . The city was named after former General Sam Houston , who was president of the Republic of Texas and had commanded and won at the Battle of San Jacinto 25 mi east of where the city was established . The burgeoning port and railroad industry , combined with oil discovery in 1901 , has induced continual surges in the city 's population . In the mid-20th century , Houston became the home of the Texas Medical Center -- the world 's largest concentration of healthcare and research institutions -- and NASA 's Johnson Space Center , where the Mission Control Center is located .   Houston 's economy has a broad industrial base in energy , manufacturing , aeronautics , and transportation . Leading in health care sectors and building oilfield equipment , outside of New York City , Houston has more Fortune 500 headquarters than any other U.S. municipality within its city limits . The Port of Houston ranks first in the United States in international waterborne tonnage handled and second in total cargo tonnage handled . Nicknamed the `` Space City '' , Houston is a global city , with strengths in business , international trade , entertainment , culture , media , fashion , science , sports , technology , education , medicine , and research . The city has a population from various ethnic and religious backgrounds and a large and growing international community . Houston is the most diverse city in Texas and has been described as the most racially and ethnically diverse major metropolis in the U.S. . It is home to many cultural institutions and exhibits , which attract more than 7 million visitors a year to the Museum District . Houston has an active visual and performing arts scene in the Theater District and offers year-round resident companies in all major performing arts .