In the beginning, creationists tried to ban the teaching of evolution altogether. Most famously, 80 years ago, John Scopes was tried for breaking a Tennessee law outlawing such instruction. He was found guilty, and evolution effectively disappeared from the high school curriculum shortly thereafter, though it continued to be taught in universities. (Related: Debate evolution)
But when university scientists began writing high school biology textbooks in the late 1950s and early '60s, evolution returned to the curriculum, provoking a second outbreak of anti-evolutionism during the '70s and '80s.
Creationism was repackaged as "creation science" in the hope that it would be taught along with evolution.
In the '70s and '80s, at least 26 states tried to legislate equal time for creation science with evolution, bringing the courts back in. The 1982 U.S. district court decision in McLean v. Arkansas- Scopes II - showed that such laws violated the First Amendment's Establishment Clause by promoting a sectarian religious idea inappropriate for the public school science classrooms. In 1987, the Supreme Court reached the same decision in Edwards v. Aguillard.
http://news.yahoo.com/s/usatoday/evolutionjustteachit