On April 6, 1968, HemisFair ’68 opened in San Antonio, Texas. It was the first official international exposition held in the Southwestern US. The fair honored the 250th anniversary of the founding of San Antonio. The fair was awarded to San Antonio on November 17, 1965. The fair’s planners estimated the cost to build up the site to be $156 million, which was paid for by both public and private funds. The fair was constructed on a 96.2 acre area in southeastern downtown San Antonio. Many existing structures were torn down, though 24 were left standing. The city also extended its River Walk into the site.