After five years of playing catch-up to the Soviet Union in space exploration, the United States has achieved its first bona fide "first" - the first successful flyby of another planet.
http://www.jpl.nasa.gov/mariner2/
View the 50th anniversary of planetary exploration interactive infographic
Take a step back in time and follow the historic story of how the United States responded to Sputnik, the world's first Earth-orbiting satellite launched by the Soviets in 1957. JPL designed and built -- and, in cooperation with the Army, launched -- Explorer 1, the first U.S. satellite and the first spacecraft ever to return scientific data from space.
PDF of the Explorer I story
Text Version
This site begins with JPL's early years in the 1930s and recounts the major historical moments for the Lab.
http://www.jpl.nasa.gov/jplhistory/
This online book provides an in-depth overview of JPL's history.
http://www.jpl.nasa.gov/about_JPL/jpl101.pdf
A timeline that covers forty years of space exploration, beginning with the first spacecraft to fly past another planet. (1962 - 2002)
http://www.jpl.nasa.gov/history/index.html
Resources for teachers
http://beacon.jpl.nasa.gov/