<P> The term "six flags over Texas" refers to several nations that have ruled over the territory . Spain was the first European country to claim the area of Texas . France held a short - lived colony . Mexico controlled the territory until 1836 when Texas won its independence, becoming an independent Republic . In 1845, Texas joined the union as the 28th state . The state's annexation set off a chain of events that led to the Mexican--American War in 1846 . A slave state before the American Civil War, Texas declared its secession from the U.S. in early 1861, and officially joined the Confederate States of America on March 2 of the same year . After the Civil War and the restoration of its representation in the federal government, Texas entered a long period of economic stagnation . </P> <P> Historically four major industries shaped the Texas economy prior to World War II: cattle and bison, cotton, timber, and oil . Before and after the U.S. Civil War the cattle industry, which Texas came to dominate, was a major economic driver for the state, thus creating the traditional image of the Texas cowboy . In the later 19th century cotton and lumber grew to be major industries as the cattle industry became less lucrative . It was ultimately, though, the discovery of major petroleum deposits (Spindletop in particular) that initiated an economic boom which became the driving force behind the economy for much of the 20th century . With strong investments in universities, Texas developed a diversified economy and high tech industry in the mid-20th century . As of 2015, it is second on the list of the most Fortune 500 companies with 54 . With a growing base of industry, the state leads in many industries, including agriculture, petrochemicals, energy, computers and electronics, aerospace, and biomedical sciences . Texas has led the nation in state export revenue since 2002, and has the second - highest gross state product . If it were a country, Texas would be the 10th largest economy in the world . </P> <P> The name Texas, based on the Caddo word tejas meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in East Texas . </P> <P> During Spanish colonial rule, the area was officially known as the Nuevo Reino de Filipinas: La Provincia de Texas (English: New Kingdom of the Philippines: The Province of Texas). </P>

Where did the name of texas come from