President Trump is slated to give his third State of the Union address on Tuesday, marking only the second time in U.S. history that an impeached president has done so.

While the State of the Union address seems like a key marker in a president’s time in office, that hasn’t always been the case.

Read on to see how the address started, how it’s changed over the years and how it’s become a tradition in Washington.

Why is there a State of the Union address?

Article II, Section 3 of the Constitution lays out that the president “shall from time to time give to the Congress Information of the State of the Union, and recommend to their Consideration such Measures as he shall judge necessary and expedient.”

Has the president always made a speech before Congress?

No. In fact, dating back to Thomas Jefferson most presidents just sent a written report to Congress. While Jefferson said he would forego a public speech because he thought it was too similar to those given by British monarchs, there is speculation that he sent written reports instead because he had stage fright.

The practice of giving written reports to Congress continued until 1913, when Woodrow Wilson decided to give a public address before a joint session of Congress

Why is it called a 'State of the Union' address?

The address was actually first known as the president’s “Annual Message” and was called such from George Washington’s first address in 1790 until 1946. The term was informally changed to the “State of the Union” in 1942 after being popularized by President Franklin Delano Roosevelt, and then officially in 1946.

State of the Union firsts

-- George Washington was the United States' first president, and thus the first to give an address. This occurred on Jan. 8, 1790, when Washington spoke to the Senate Chamber in New York City.

-- Calvin Coolidge gave the first radio broadcast of his address on Dec. 6, 1923, while Harry S. Truman delivered the first televised address on Jan. 6, 1947, but it wasn’t until Jan. 4, 1965 that Lyndon B. Johnson gave the first address on primetime television. George W. Bush is the first president to have his State of the Union address broadcast via the internet.

-- The first “designated survivor” was during the Cold War of the 1960s amid fears of a nuclear attack, although official records weren’t kept until years later. The first official member of the cabinet to have that role was in 1981 when Ronald Regan tapped Education Secretary Terrel Bell to be rhe “designated survivor.”

What president has given the most State of the Union addresses?

That title goes to FDR, who gave 12 address, 10 of which were delivered in person.

Who has given the longest address?

Jimmy Carter had the longest written State of the Union speech, which included more than 33,000 words, but the address was not spoken. Bill Clinton gave the top two longest in-person speeches: 1 hour and 28 minutes in 2000; and 1 hour and 24 minutes in 1995.

Have any presidents not given a State of the Union address?

Only two.

William Henry Harrison and James Garfield are the only presidents who did not give a State of the Union address. Garfield was in the White House for a little more than six months before he was assassinated; Harrison was president for only one month before succumbing to pneumonia.

Fox News’ Kaitlyn Schallhorn contributed to this report.