It's a marquee night for President Donald Trump, who was scheduled to deliver his first remarks to a joint session of Congress on Tuesday. It has been talked about as a State of the Union address, but technically that's not a correct designation for the speech.

The address might seem like a State of the Union speech because it was expected to detail Trump's vision for America and ring a bit more optimistic than the president's usual messaging. Trump's own camp sent an email to supporters Monday with the subject line simply reading "State of the Union."

"Before President Trump delivers his biggest speech to date, he wants you to provide your input on the direction of our country," it read. "He is taking the podium to voice your concerns, thoughts, and opinions about the state of our nation, and more importantly, to lay out a bold plan for our future as Americans."

Regardless, Trump's speech remained an address to a joint session of Congress because the president must be invited to give an official State of the Union speech, which traditionally takes place after a full year in office. 

The tradition came from the Constitution, which stated 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."

The Speaker of the House, however, invites the president to deliver speeches and determines what the address should be called. As such, House Speaker Paul Ryan invited Trump to "address a joint session of Congress," even if it will look, sound and feel like a State of the Union speech. 

There has long been a State of the Union address, but former President Ronald Reagan, a Republican icon, started the tradition of delivering a speech about one month into an administration. The speech was dubbed "Address Before a Joint Session of the Congress on the Program for Economic Recovery."