Marshall Space Flight Center in Huntsville would help Alabama's economic growth in the mid-to-late 20th century, by developing an aerospace industry. Alabama's economy in the 21st century is based on automotive, finance, tourism, manufacturing, aerospace, mineral extraction, healthcare, education, retail, and technology. The state's geography is diverse, with the north dominated by the mountainous Tennessee Valley and the south by Mobile Bay, a historically significant port. Politically, as part of the Deep South, Alabama is predominantly a conservative state, and is known for its Southern culture. Within Alabama, American football, particularly at the college level at schools such as the University of Alabama, Auburn University, Alabama A&M University, Alabama State University, Troy University, the University of South Alabama, and Jacksonville State University, plays a major part of the state's culture. Etymology The European-American naming of the Alabama River and state was derived from the Alabama people, a Muskogean-speaking tribe whose members lived just below the confluence of the Coosa and Tallapoosa rivers on the upper reaches of the river. In the Alabama language, the word for a person of Alabama lineage is (or variously or in different dialects; the plural form is ). The word's spelling varies significantly among historical sources. The first usage appears in three accounts of the Hernando de Soto expedition of 1540: Garcilaso de la Vega used , while the Knight of Elvas and Rodrigo Ranjel wrote Alibamu and Limamu, respectively, in transliterations of the term. As early as 1702, the French called the tribe the , with French maps identifying the river as . Other spellings of the name have included Alibamu, Alabamo, Albama, Alebamon, Alibama, Alibamou, Alabamu, Allibamou. and possibly Alabahmu. The use of state names derived from Native American languages is common in the U.S.; an estimated 27 states have names of Native American origin. Sources disagree on the word's meaning. Some scholars suggest the word comes from the Choctaw (meaning 'plants' or 'weeds') and (meaning 'to cut', 'to trim', or 'to gather'). The meaning may have been 'clearers of the thicket' or 'herb gatherers', referring to clearing land for cultivation or collecting medicinal plants. The state has numerous place names of Native American origin. However, there are no correspondingly similar words in the Alabama language. An 1842 article in the Jacksonville Republican proposed it meant 'Here We Rest'. This notion was popularized in the 1850s through the writings of Alexander Beaufort Meek.