The Simpsons are household names all over the world

Only one in four could name more than one of the five freedoms it upholds but more than half could name at least two members of the cartoon family.

About one in five thought the right to own a pet was one of the freedoms.

A new museum dedicated to the First Amendment said the findings showed there was a pressing need to explain one of America's basic laws better.

"We have our job cut out for us," said Joe Madeira, director of exhibitions at the McCormick Tribune Freedom Museum.

Another finding from the poll, a telephone survey of 1,000 random adults with an error margin of 3%, was that 22% of Americans could name all five Simpson characters.

By comparison, just one in 1,000 people could name all five First Amendment freedoms.

The names of American Idol TV show judges and popular advertising slogans also proved more memorable than the five freedoms - speech, religion, press, assembly and petition for redress of grievances.