President Bush's annual State of the Union address to Congress and the American people Tuesday is the latest installment of a Washington ritual that dates back to the time of the first U.S. president, George Washington. 

"Mr. Speaker, the president of the United States!"

With that familiar introduction in the U.S. House chamber, an American president prepares to deliver the annual State of the Union address to a joint session of Congress.

President George Washington delivered the first State of the Union address in 1790.  But for more than 100 years beginning in 1801, presidents sent a written version of their address to Congress that was read out loud by a clerk.  It was President Woodrow Wilson who re-established the practice of delivering a State of the Union speech in person, in 1913.

In 1923, Calvin Coolidge became the first president to have his State of the Union address broadcast on radio.

For many years, the address was simply referred to as the President's Annual Message to Congress.  It was President Franklin Roosevelt, in 1935, who began the practice of referring to the speech as the State of the Union Address. 

President Harry Truman delivered the first State of the Union address on television in 1947.

The requirement for the annual address stems from the U.S. Constitution.  It mandates that the president "shall from time to time give to Congress information on the State of the Union."

In the modern era, State of the Union speeches have become an opportunity for the president to lay out a lengthy series of specific policy proposals on a wide range of issues.

"The State of the Union address has become the way in which the president sets the agenda for Congress and speaks to the American people about his accomplishments and hopes for the future," said Stephen Wayne, an expert on U.S. politics at Georgetown University in Washington.  "It is part of our political tradition.  There is a lot of ceremony attached to it.  And that usually works to the benefit of the president."

Historically, presidents have also used the State of the Union Address to inspire lawmakers and ordinary citizens alike to attain loftier goals.

The State of the Union also provides the president with an opportunity to build support for his policy proposals among both houses of Congress and the general public.

"The State of the Union is one of those events that have symbolic importance for the country," said Thomas Mann, a political analyst at the Brookings Institution in Washington.  "It is an occasion of pomp and tradition.  It involves a nationally televised audience.  It is an opportunity for the president to try to shape the policy-making agenda, to influence public opinion."

The process of writing and rewriting a State of the Union speech can take months.  Ray Price recalled his experience as a speechwriter for President Richard Nixon.

"We would normally go back and forth through about seven or eight drafts.  I would edit him, he would edit me, I would edit him, he would edit me as he was thinking the thing through," he said.

Ronald Reagan took the State of the Union Address to new heights during his presidency in the 1980s.  He began the practice of introducing well-known figures as well as private citizens notable for some achievement, who were sitting in the House Gallery.  These guests are usually interwoven into the president's speech.  The practice has proved to be popular and has been repeated by all the presidents who followed Mr. Reagan in office.