1) The Hitchhiker's Guide to President Biden's speech to Congress. Let’s get one thing out of the way first.

President Biden’s speech to a Joint Session of Congress is not a State of the Union speech.

2) It’s not unheard of for people to colloquially refer to a President’s initial speech before a Joint Session of Congress early in their first term as “State of the Union.” But technically it’s not a “State of the Union.”

3) That’s because the newly-inaugurated President has only been on the job a short time.

However, President Biden has been more than “on the job” for a while now. The President initial address to Congress comes 98 days after he was sworn-in.

4) That’s the latest for any modern President. Most recent Presidents have given their first speech to Congress about a month after taking office, usually in mid to late February. President Reagan spoke to Congress on February 18, 1981, just 29 days into his first term.

5) Only expect a grand total of 200 people inside the chamber for the speech. That’s just a fraction of how many they usually squeeze into the chamber for a speech of this caliber. About 80 House members. Sixty senators.

6) There are 445 fixed chairs on the House floor. They typically haul in about 140 temporary chairs. There are 660 seats in the viewing gallery above the chamber. And finally, Congressional officials can shoehorn about an additional 300 to 400 people into the chamber, standing.

7) Throw in the network TV pool and you’re staring at well over 1,600 people jammed into the House chamber. Not this time.

Lawmakers won’t be allowed to camp out on the center aisle hours in advance to gab a key seat to glad-hand the President.

8) In fact, it’s unclear if there will be any glad-handing at all. Maybe glad-elbowing.

Members aren’t permitted to bring guests. Usually lawmakers like to show off a hometown hero, a nurse or a member of the military. Not this time.

9) In addition, the House even adopted a special rule recently barring former members from coming to the floor for the speech.

U.S. Chief Justice John Roberts is the only member of the Supreme Court invited.

10) The same with Mark Milley, Chairman of the Joint Chiefs of staff. Secretary of State Tony Blinken and Defense Secretary Lloyd Austin will represent the Cabinet.

There is no designated survivor from the Cabinet tonight.

11) Treasury Secretary Janet Yellen falls in the line of succession between Blinken and Austin. Behind Austin is Attorney General Merrick Garland.

Moreover, a new face will introduce President Biden to the Joint Session of Congress.

12) Pelosi just swore-in William Walker, the former head of the Washington, DC National Guard, as the new Sergeant at Arms. Walker succeeds former Sergeant at Arms Paul Irving. Pelosi asked for Irving’s resignation after the January 6 riot.

13) Walker is the first African American to hold the post. On Wednesday night, Walker will stride into the chamber, down the center aisle and declare “Madam Speaker! The President of the United States!”

14) Walker will escort the President in through the center door to the chamber. That’s the same door in which lawmakers shoved furniture to protect themselves during the riot on January 6. There are iconic pictures plainclothes officers standing at that door, guns drawn.

15) When Mr. Biden speaks, he’ll do so, standing one level below 2 women on the dais: Pelosi, as Speaker & Vice President Harris, serving in her capacity as President of the Senate. It’s the first time two women will co-preside over a Jt Session with the President.

16) The President will wear a mask when he enters the chamber but will remove it when speaking from the dais.

“State of the Union” addresses have morphed through the years. The act itself is not even a requirement. And, there’s no mandate that the President even give an address

17) Article II, Section 3 of the Constitution simply says the President “shall from time to time give to the Congress Information on the State of the Union.”

President George Washington delivered the first such speech to Congress in 1790 – in New York.

18) But President Thomas Jefferson discontinued the practice of a speech in 1801. He thought the enterprise mirrored England and a speech from “The Crown.” So Jefferson submitted missives to Congress instead.

19) The concept of a “speech to Congress” lay dormant for more than a century. President Woodrow Wilson resurrected a speech to Congress in 1913. Wilson even delivered a State of the Union speech to Congress on December 2, 1918.

20) The House had just shut down for about a month due the Spanish Flu pandemic in October. Congress reopened for business in early November. Wilson spoke a month after that.

21) Wilson spoke extensively about World War I, railways and international peace. But he never once mentioned the pandemic.

22) President Calvin Coolidge was the first to have his speech broadcast on radio in 1923. President Franklin Delano Roosevelt was the first to call it “State of the Union” in 1934. Congress formally adopted the “State of the Union” vernacular about a decade later.

23) President Harry Truman delivered the first State of the Union speech on TV in 1947. President Lyndon Baines Johnson shifted the speech to prime-time in 1964.

24) Tonight's speech may mark the most significant changes to such an address since it was first put on radio or moved to prime-time TV