Explorers from Spain began visiting the Americas more than 500 years ago, and their presence has been felt ever since. The United States is indebted to the rich legacy Hispanics have left behind and the contributions they have made to the foundations of this country. Hispanic-Americans have broken down barriers, blazed new trails, and expanded our social and intellectual boundaries.Nobel Prize winners Mario Molina and Luis Alvarez broke new scientific ground and extended the realm of knowledge. Cesar Chavez, the iconic labor organizer, popularized the idea of buelga - strike - in the Southwest and changed the working lives of migrant workers for the better. Astronauts Ellen Ochoa and Carlos Noriega have gone where very few humans have: into outer space with NASA's shuttle program. In the late 1800s, Maria Amparo Ruiz de Burton became the first Hispanic author to write for an English-speaking American audience. She has been followed in modern times by novelists Sandra Cisneros, Isabel Allende, and Oscar Hijuelos, whose The Mambo Kings Play Songs of Love became the first novel by a Hispanic-American writer to win a Pulitzer Prize. Read Less