In September 1968, Congress authorized President Lyndon B. Johnson to proclaim National Hispanic Heritage Week, which was observed during the week that included September 15 and September 16. In 1988, Congress expanded the observance to a month-long celebration (September 15 - October 15), and the change became effective in 1989.
The United States celebrates the culture and traditions of those who trace their roots to Spain, Mexico and the Spanish-speaking nations of Central America, South America and the Caribbean.
September 15 was chosen as the starting point for the celebration because it is the anniversary of independence of five Latin American countries: Costa Rica, El Salvador, Guatemala, Honduras and Nicaragua. In addition, Mexico and Chile celebrate their independence days on Sept. 16 and Sept. 18, respectively.
(Source: PR Newswire)