Eliza Hamilton (formerly Schuyler) gasps at the very end of Hamilton's last song, "Who Lives, Who Dies, Who Tells Your Story", but what does the moment mean? While much of Hamilton's plot focuses on the rivalry between its titular character, Alexander Hamilton (Lin-Manuel Miranda), and his political rival Aaron Burr (Leslie Odom Jr.), it's the lead character's wife Eliza who provides the musical with so much of its emotion and heart, as evidenced in powerful musical numbers such as "Burn".
That proves true in Hamilton's ending, when after Alexander's death at the hands of Burr, much of that last song is given over to her. The story provides a snapshot of her own life following the loss of her husband, such as her work founding an orphanage in New York, and she also sings of being with Alexander again at some point in the future (with Miranda briefly re-joining her on stage). At the very end of the song, Eliza steps forward to be front and center of the stage herself, lets out a piercing gasp, clutches at her chest, and then the lights go out.
It's not only Hamilton's last moment, but one of its most intriguing and open to interpretation, with two major schools of thought. Given that a lot of "Who Lives, Who Dies, Who Tells Your Story" finds Eliza singing of being reunited with Alexander, with lines like "Oh, I can't wait to see you again / It's only a matter of time", then it's very possible that's what is happening in this final scene. Eliza's gasp and clutching at her chest would signify not only her death, but her finally getting to see Alexander once more as he greets her in the afterlife. The notion of seeing loved ones again is addressed in the penultimate song, "The World Was Wide Enough", where Alexander catches "a glimpse of the other side," seeing fallen friends and family members, including his mother, his son Philip, John Laurens, and George Washington. Eliza gasping, then, would represent her now seeing the other side too.
The other possibility is that Hamilton is actually having Eliza break the fourth wall here instead. She looks out at the audience as she gasps, which could indicate that the shock she experiences in this moment is at seeing the crowd of people in front of her. Thematically, this fits nicely with the final song, as she sees all the people listening to her story, answering the key question of the final song. Alexander's story, and indeed Eliza's, will be told by those in front of her. In some versions of the production, Eliza has even pointed at the audience, further suggesting that this is the intended meaning. Given the musical opens with the main players introducing themselves, as though directly to the audience, then it's not much of a stretch to think it would close with a similar addressing of the crowd.
Of course, part of the beauty of the moment is in its ambiguity, and how all interpretations are valid and down to the viewer. Phillip Soo, who plays Eliza in the version of Hamilton streaming on Disney+, has spoken about this herself, saying in an interview with BroadwayGirlNYC: "People are like, ‘Is it Eliza going into heaven? Is she seeing Alexander? Is she seeing God? What is it?’ And it’s kind of all of those things. Sometimes, it’s literally, I look out and I see the audience, and that’s what it is, but I think, that idea of ‘transcendence’ is present in all of that." Whether this is Eliza breaking the fourth wall, being reunited with Alexander, both, or something else, there's no doubt it makes for a powerful ending to Hamilton.