As Americans get ready to tune into President Obama's State of the Union address on Tuesday night, most of us think we know the basics about the annual speech.
The State of the Union is a speech delivered by the president every year, in January or February, to a joint session of Congress. Typically, the chief executive lays out his or her policy objectives for the upcoming year.
The house speaker and the vice president sit behind the president, trying to appear attentive and interested, and not be caught on camera doing anything embarrassing in an unguarded moment.
Also, the U.S. Supreme Court is in attendance, making it one of the few times that all three branches of American government are represented at one event.
Although the president's cabinet attends the address, one member always stays away from the event. That occurs in case there is some sort of natural disaster or attack, and the surviving cabinet member is needed to assume the presidency.
The U.S. Constitution requires the president give a State of the Union message to Congress occasionally on the nation's condition.
Article II, Section 3 states, "The President shall from time to time give to Congress information of the State of the Union and recommend to their Consideration such measures as he shall judge necessary and expedient."
But the Constitution doesn't require it be done annually.
If a president chose, he or she could do just one during their term or could even do it monthly – although the latter option would likely diminish its potential impact.
Also, the constitution doesn't require the speech be given at the Capitol or even be presented in-person at all.
In fact, for a long period in American history, presidents preferred merely to send a written report to Congress.
The first two presidents – George Washington and John Adams – gave speeches to Congress. But beginning with Thomas Jefferson, a written report was prepared instead. He thought a formal speech looked too regal, and reeked of the monarchy that early Americans had just jettisoned.
Jefferson's tradition lasted for 112 years, until Woodrow Wilson in 1913.
It wasn't until Franklin Roosevelt in 1934 that the steady tradition of delivering the speech in-person to Congress began.
Additionally, that was when the address was first referred to as the "State of the Union," but the term didn't stick until 1947, according to historian Robert Schlesinger.
Calvin Coolidge was the first president to give a State of the Union address over the radio, in 1923.
Harry Truman was the first president to give his State of the Union address on television, in 1947.
And it was Lyndon Johnson in 1965 that first gave a State of the Union at night, in TV's primetime viewing period. Before that year, the speeches were given in the afternoon while many people were at work or school.
A total of four presidents -- Ronald Reagan in 1981, George H. W. Bush in 1989, Bill Clinton in 1993 and George W. Bush in 2001 – choose not to give a formal State of the Union during their first year in office, deciding it would be too soon after their inaugural address.