As Barack Obama prepares to deliver his annual State of the Union address to Congress, I thought it a good time to take a look back at this most unique event in American politics. So I’ve gathered images from previous presidential SOTU addresses, from President Woodrow Wilson’s in 1918 to President Obama’s in 2010. I couldn’t find any for Warren G. Harding, and Herbert Hoover made no public appearances before Congress (probably a good move).

Appearing in this gallery are Presidents Barack Obama (2010), George W. Bush (2008), Bill Clinton (1999), George H.W. Bush (unknown date), Ronald Reagan (1988), Jimmy Carter (unknown date), Gerald Ford (1975), Richard Nixon (1971), Lyndon Johnson (1968), John F. Kennedy (1963), Dwight Eisenhower (1960), Harry S. Truman (1953), Franklin Delano Roosevelt (1941), Calvin Coolidge (1923), and Woodrow Wilson (1918).

For political junkies, here’s a few interesting State of the Union facts:

• Article II, Section 3, clause 1 of the United States Constitution authorizes the State of the Union Message, stating: “He [the President] shall from time to time give to the Congress Information on the State of the Union, and recommend to their Consideration such measures as he shall judge necessary and expedient.”
• George Washington delivered the first regular annual message before a joint session of Congress, in New York, on January 8, 1790.
• Thomas Jefferson, who felt that a public speech such as this reeked a little too much of monarchy, changed the procedure followed by his predecessors with his first annual message (December 8, 1801).
• Every president after Jefferson followed his lead and simply kept Congress informed of their activities with a long, written message.
• Woodrow Wilson revived the SOTU as a public speech in 1913, although not every one since has been delivered personally.  22 of them, specifically, have been written only.
• The message was generally known as “the President’s Annual Message to Congress” until well into the 20th century. Although some historians suggest that the phrase “State of the Union” emerged only after World War II, Franklin D. Roosevelt’s 1934 message is identified in his papers as his “Annual Message to Congress on the State of the Union.”
• Two Presidents did not serve long enough to submit an annual message: William Henry Harrison, who died in 1841, 32 days after his inauguration, and James A. Garfield, who was assassinated in 1881 and served only 199 days.
• The first SOTU broadcast on radio was President Calvin Coolidge’s speech in 1923.
• The first televised SOTU address was delivered by Harry Truman in 1947.
• Lyndon Johnson moved the address from its traditional midday slot to the evening in order to attract a large television audience.
• Since the Cold War era, at least one member of the President’s Cabinet has been holed away in an undisclosed location during the address in order to ensure continuity of government in case the shit hits the fan.