Lafayette ), is a city in and the parish seat of Lafayette Parish, Louisiana, United States, on the Vermilion River. The population was 120,623 at the 2010 census; It is the fourth largest city in the state. It is the larger principal city of the Lafayette-Acadiana, LA Combined Statistical Area, which, in 2007, had an estimated total population of 538,470.This city should not be confused with one of the same name in Jefferson Parish, Louisiana, and which was absorbed into New Orleans. It was founded as Vermilionville in 1821 by a French-speaking Acadian named Jean Mouton. In 1884, it was renamed for General Gilbert du Motier, marquis de Lafayette, a French military hero who fought with and significantly aided the American Army during the American Revolutionary War. The city's economy was primarily based on agriculture until the 1940s, when the petroleum and natural gas industry became dominant. In recent years, the medical profession has taken a more predominant role in the area economy.Lafayette is the center of the Cajun culture in Louisiana and the US. Lafayette has a strong tourism industry because of the Cajun and Creole cultures of the surrounding region. The cuisine of the region, Cajun cuisine, is one of the most famous regional cuisines in the US.