for much of the 20th century, and even the county seat Bartow has had several large groves. In 1941, the city built an airport northeast of town in the county. The airport was taken over by the federal government during World War II and was the training location for many Army Air Corps pilots during the war. The airport was returned to the city in 1967 and renamed as Bartow Municipal Airport. Mid-20th century to present In the 20th century, the Ku Klux Klan revived and was active in Polk County, even after World War II. Klansmen were photographed in hoods and robes in 1958 in a church in Mulberry. During the 1960s violence related to civil rights movement was attributed to the Klan. In 1967, a white man shot and severely wounded a popular African-American high school football player who was integrating Lake Ariana Beach. A Klan group marched in Lakeland in full regalia in 1979, their last public march by the Confederate monument in Munn Park. Fred Rochelle, 16, was burned alive in a public spectacle lynching before thousands in Polk County, Florida, in 1901. Since the late 20th century, growth in Polk County has been driven by its proximity to both the Tampa and Orlando metropolitan areas along the Interstate 4 corridor. Recent growth has been heaviest in Lakeland (closest to Tampa) and the Northeast areas near Haines City (nearest to Orlando). From 1990 to 2000, unincorporated areas grew 25%, while incorporated areas grew only 11%. In addition to cottage communities that have developed for commuters, Haines City has suburban sprawl into unincorporated areas. Despite the impressive growth rate, the unemployment rate of Polk has typically been higher than that of the entire state. For example, in August 2010, the county had an unemployment rate of 13.4%, compared to 11.7% for the entire state. During the 2004 Atlantic hurricane season, three hurricanes, Charley, Frances and Jeanne, all tracked over Polk County, intersecting in a triangle that includes the city of Bartow. Winter Haven was best known as the home of the Cypress Gardens theme park, which operated from 1936 to September 23, 2009. Legoland Florida has since been built on the site of former Cypress Gardens, and has preserved the botanical garden section. Winter Haven was the location of the first Publix supermarket circa 1930; today Publix's corporate offices are located in Lakeland. In 2018, the Lakeland