Its title is "The Star-Spangled Banner". This refers to the American flag and its stars.

The lyrics (words) were written by Francis Scott Key in 1814. Key watched a battle of the War of 1812. The British Navy fired on Fort McHenry in Maryland. The attack went on all night, but in the morning the American flag was still flying over the fort. Key wrote a poem about this, called "The Defense of Fort McHenry".

The music was taken from a song by John Stafford Smith. Smith was an English composer. He called the tune "The Anacreontic Song". People began singing Key's poem to this song's music.

Congress voted to make it the National Anthem in 1931. However, Americans had considered it their anthem long before that. The song was popular from the time it was first set to music.

The National Anthem is always played at professional baseball games. This custom began during the World Series of 1917, when the U.S. was at war. Now, it's a part of all professional baseball games, and famous singers are often asked to perform it then. Some Americans, when they hear the Anthem ending, always expect to hear someone say "Play ball!" - whether they're at a ballgame or not.

It can be hard to sing. Many people complain that the opening notes are too high. Still, most Americans have learned the song and try to sing it when it's called for.

Usually, just the first verse is sung. There are three more, but most people don't know them.

Some of the song's words have become common expressions in American English. For example, you may hear people say, "Oh, say, can you see?" or "land of the free" or "dawn's early light".So Proudly We Hail! is the title of a movie about war nurses, made in 1943.

The U.S. government has ruled that everyone should stand when the Anthem is played. Military members salute. Civilians should take off their hats and put their right hands over their hearts. Citizens of other countries are asked to stand, also.

You can read the words and hear the music here http://kids.niehs.nih.gov/games/songs/patriotic/anthemmid.htm#history Warning: The site starts playing the music as soon as you open it.