Censorship started in 399 B.C. when Socrates was sentenced to death for being accused of corrupting youth. A strong need for censorship did not come about until the printing press was invented.
After the printing press was invented in the 15th Century, censorship became a part of the world. In some countries, censorship was enforced so severely that punishments were handed out for acts of free speech. In the United States, formal censorship was never enforced, but libel lawsuits came about on some occasions of free speech. As time has went on, free speech has become part of culture in some countries such as Britain while others, such as Iran and parts of Africa, continue to strictly enforce censorship.