Among them that evening was army spouse Amy Williams and her two children. Mr Trump introduced them to the room towards the end of his speech by commending her for carrying on while her husband, Sergeant Townsend Williams, was deployed in Afghanistan over the past seven months.
But then, in what people call typical Trump grandeur given his history in reality TV, he revealed Mrs Williams's husband had returned from deployment and was there that evening.
Congress stood to cheer, people wiped tears from their eyes, and others high-fived while looking on at an emotional reunion between the couple and their two children. Chants of "USA, USA" reverberated through the House of Representatives chamber, all during the intimate family moment.
People watching from home shared the reunion video far and wide on social media. But what was largely left unsaid was the sucker punch the moment left some service members and their spouses feeling, all of whom have experienced how agonising homecoming reunions can be.
Rebekah Sanderlin of Colorado Springs, Colorado, is a spouse of an active service member in the Army Special Forces, whom she did not name due to his position. Together, the couple have experienced an estimated 20 deployments — during their almost 17-year-long marriage. These reunions started out just between the two of them but then later included their three children: Bo, 15, Rudy, 11, and Lucy, seven.
For her, when watching the State of the Union, she felt the raw emotions Mrs Williams must have been going through. She described the moment as "reunion porn".
"I don't criticise that couple at all," Mrs Sanderlin said. "Everybody has their own approach and far be it for me to decide for someone else. What made me want to say something was I was seeing a lot of discussion online [about the moment]. There didn't seem to be much understanding of the depths of the issue.
"There are a lot of us who refer to this as reunion porn because the show is for the benefit of the viewer, not the participant."
In a Twitter thread, Mrs Sanderlin detailed for her followers the reality of homecoming reunions for a lot of military families, including the awkwardness a couple can feel towards each other.
She wrote: "It's awkward. Because this is, effectively, a stranger. You haven't seen him in so long, and so much has happened, to both of you, since he left...You need to process that it's really over. He really did make it home. You never let yourself dare to believe that would happen. You need a minute. You need a day...You need no one watching."
When detailing past reunions, Mrs Sanderlin admitted she had no clue as to the range of emotions she would feel once her husband returned.
"The first time he deployed we had been married for two weeks," she said. "Since it was our first experience with that I just wasn't prepared for the rawness of the emotions that I felt. We were newlyweds. I wasn't expecting there to be conflicting emotions."
Spouses can experience a level of abandonment by their service member. Upon the service member's return, it can be made more confusing by the moments that were missed the months they were away.
"The reintegration period after a deployment in a lot of ways is worse than the deployment," she added. "You have to learn to be a family again, you have to learn to be a couple again."
Her take on the president's surprise resonated with other military families who also felt a similar awkwardness.
Linda Tirado of Nashville, Tennessee — whose spouse, Tom Tirado, is a retired Marine Corps sergeant — said she experienced conflicting emotions during their own homecoming reunions.
"This person is a world away and going through insanely traumatic s***," she said. "You don't know who is going to come home, but you know it is not going to be the same person who left you."
Her frustration with the State of the Union came from Mrs WIlliams being blindsided by Mr Trump and his administration. The White House and Williams family were unavailable to comment on this story.
"This woman did not give her consent to have her reaction in the public eye on an international level," Mrs Tirado said. "It's fine if you found [the moment] heartwarming, it is heartwarming. Thank God that man came home safely ... But that still doesn't justify the lack of consent, the exploitation of this reunion.
"It just was ridiculously offensive that you would take that moment and turn it into a show."
Neither of the military spouses thought Mrs Williams had a clue her husband was home, making it gut-wrenching to endure.
"For military families, we were all thinking, 'OK this is great they are home.' But we know that they have a solid six months of fighting ahead of them," Mrs Sanderlin said. "They're facing a long road. No couple reintegrates without fighting."
After watching the State of the Union, Mrs Tirado also shared her thoughts with her own Twitter following. She confessed she would be angry at her Marine husband for showing up unannounced.
"Imagine rocking up to your whole family who thought you were in mortal danger and you've been safe for entire days, and you do it live at the State of the Union," she wrote. "I'd be f***ing homicidal and I make no apologies, how the f*** dare you."
She believed the heartwarming moment still could have a place during the State of the Union, but wanted the administration to instead allow the family to reunite privately before the address and then walk in together.
"They didn't not have to surprise her with it and get her candid reaction when she's sitting there with two kids," Mrs Tirado said.
Compared to the viral reunion videos people typically see on YouTube, Mrs Tirado thought the lack of consent during the State of the Union was a big red flag.
"You get your viral videos but those are filmed and posted with consent," she said. "Those people are emotionally prepared to be reunited."
Other people online echoed similar sentiments as both women, accusing Mr Trump of using this moment to get an emotional reaction without thinking of how it would exploit the wife and her two children.
Gold Star families — which refers to people who lost loved ones in military service — were also in attendance, and it added another layer of discomfort to the reunion surprise.
"They don't get to have that reunion," Mrs Sanderlin said.
She made it clear, though, her frustration towards the moment was not focused on Mr Trump or his administration. Instead, she hoped the public would take these viral reunions and use them to better understand what service members and their family members go through during deployment and when they're reunited.
"My goal is for people to think more about all the stuff that is going on for this family beyond that they are back together," she said. "And I would hope that maybe the next time they hear the troops are being deployed they think about all the stuff that will happen to the family before they get the reunions."
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