Flag Day, June 14th, commemorates the day, in 1777, when the basic design for the "stars and stripes" was approved by the U.S. Continental Congress. Today, our "Grand Old Flag" is one of the most widely-recognized symbols in the world. In this era, the American flag evokes a complicated set of feelings, but the Congressional resolution which made the star spangled banner our national flag was simple. It said "Resolved that: the flag of the United States be thirteen stripes alternate red and white, that the Union be thirteen stars white in a blue field representing a new constellation"

According to Whitney Smith, director of the Flag Research Center and the author of more than two dozen books about flags, the horizontal stripes, and ring of stars simply denoted the number of states fighting for independence from the British crown.

"But they were already expressing some of their ideals," he says, "because the ring of stars is symmetrical, it is never-ending; it is equal in the sense that no star is any larger or has any greater significance than the other ones."

A flag can be a national symbol because it represents a country in an abstract way. But, says David Phillips, director of the North American Institute of Heraldic and Flag Studies, a great flag is also a sign.

"One thing that makes a flag really effective is that it be clear, so that it is visible at sea, [and] it's visible if it's flapping in the wind," he says. "The United States flag is clearly visible at a distance even if its wrapped around a pole you are able to see the stripes." That's because red and white and blue are an extremely effective visual combination. There is high contrast. "Whereas, if you wanted to have red and orange, that wouldn't work very well," says Phillips.

Phillips notes that other national flags have emulated the American design. "Liberia for example, which was founded as an American colony, and Malaysia which has 14 stripes and a blue canton, and Uruguay, which looks like the American flag although the colors are different. Togo, the same way. Still, people recognize the American flag."

The display of a flag addresses the universal desire to distinguish one's own group from other groups. Whitney Smith likens flags to the special feathers worn only by a tribal chief and to forms of dress denoting different social or military ranks.

"The social unity of many groups is very much associated with, and reflected, in marks that are given meaning, Whitney says. "You can see it in gangs in junior high school, for example, and you can see it in other situations where people feel they've got to be 'one of the guys' or they've got to be the ones from the 'right side of town.' That's what flags are all about."

There is no international legal requirement to have a flag, yet every member state in the United Nations flies its own banner. Actually, national flags -- in the modern sense -- are a relatively recent development. Most scholars agree that Denmark's flag of 1219 - a white cross on a red field - is the oldest national flag. But Smith says the American flag marked a departure in who and what national flags were meant to represent.

"We started out without a king, without an aristocracy, without even a common language," he explains. "We didn't base our society on race. We didn't have a single religion that everyone adhered to. And that was extraordinary because one or another of those characteristics was very much what other countries were based on." By contrast, Smith says, "in the United States, we say 'it is the principles that we operate under.' Those can be kind of dry and abstract for a lot of people. So the flag is a way of transmitting that idea."

Smith says the American flag was the first flag that "people considered their own - not the government's, but theirs." He notes that Americans display their flag extensively everywhere, and that schoolchildren in the United States recite a pledge to it. "It has rituals, songs, and a special day associated with it. All of those things basically came first with the American flag."

Today, the meanings of the American flag are as diverse as the people who see it and use it: Some see it is a symbol of unity, others of diversity. For many people, the American flag symbolizes freedom and democracy. When others see it, they think of Western imperialism. Flag scholar David Phillips offers other ideas of how Americans might view the "star spangled banner" on Flag Day.

"They could look up and think of all the places that flag has flown and all the things it's been through. They could think about our civil war. They could think about the landings at Anzio [Italy, during World War II]. They could think about, if they wish to, about our present military expeditions. And they can think about all the things that flag has meant to people all over the world and people who have arrived here fleeing from other places."

Whatever the emotion or association, there will be many opportunities to experience them, as flags fly on June 14th.