WASHINGTON - Americans celebrate the 215th anniversary of their Constitution today, even though most of them admit they don't know much about what's in it.

Although only 16 percent of adult Americans say they have a "detailed" knowledge of the document, a strong majority agree with its bedrock principle -- that the country should follow the will of the majority while protecting the rights of minorities, according to a survey taken to mark the anniversary.

A solid majority, 66 percent, say they have a general understanding of the document, which frames America's structure of government and guarantees its citizens their rights.

The constitutional convention approved the document on this date in 1787, and it was ratified by the states the following year. It was declared in effect on March 4, 1789.

Nearly nine out of 10 of those surveyed, or 87 percent, said they agreed with the Constitution's underlying values.

"This survey shows that if the text of the Constitution is captured imprecisely in people's heads, its principles and values are alive and well in their hearts," said Joseph Torsella, president of the National Constitution Center.

The center, established by Congress to increase understanding of the Constitution, commissioned the poll, which was conducted by Public Agenda, a research group based in New York. The survey of 1,530 adults was conducted in July and had a margin of error of plus or minus three percentage points.

The polling was financed by the John S. and James L. Knight Foundation. The Knight brothers' foundation was formed in 1950 as an enterprise separate from their newspaper business. That business has evolved into Knight Ridder Inc., which owns 31 daily newspapers in the United States, including The Kansas City Star.

Despite general agreement with the Constitution, many Americans harbor doubts that its ideals have been achieved, and few want it forced on other nations:

• Sixty-five percent say the rich and powerful have more rights than others.

• Sixty-six percent say the United States should help other countries replicate the Constitution only if they ask.

• Forty-one percent say the right to privacy is threatened, and 24 percent say they think the right is already lost.

• Fifty-seven percent see banks and credit card companies as the biggest threats to privacy, and 29 percent see the federal government as the biggest threat.

Freedom of the press is the least popular right guaranteed by the Constitution: 43 percent of those surveyed said the Founding Fathers went too far.

The right to keep and bear arms is the most divisive, with 32 percent saying the Founding Fathers went too far and 26 percent saying the right has been too restricted.

To reach Steven Thomma, e-mail sthomma@krwashington.com.

On the Web

• National Constitution Center: www.constitutioncenter.org