Character Analysis
Peter Warne's an impoverished newspaperman who's part clown and part tough guy, and he's got a heart of gold. To put the cherry on top, he's also a hopeless romantic underneath his gruff exterior. This becomes clear as soon as he starts to look after Ellie Andrews—which is pretty much right after he meets her. And his chivalry is that much more remarkable, since it contrasts with his stated opinion of Ellie—he thinks she's totally spoiled. (He's kind of right.)
Here's what we mean: Peter keeps saying that he has nothing but disdain for the rich in general, and in particular for spoiled brats like Ellie. But his behavior suggests otherwise: For example, he takes over Ellie's expenses when he realizes that she can't manage money on her own. (She's never had to.) He does all kinds of nice things for her: He gives her a piggyback ride, makes her a bed, forages for food for her, and just generally has her back. All of these caring gestures clue us in and prepare us for his grand declaration of love later.
A Good Man is Hard to Find
Of course, several more obstacles have to be overcome before Peter and Ellie can end up together and win their "mad fight to happiness."
That's where the suspense of It Happened One Night comes from, and it's part of the fun of watching the film. But once Peter realizes that he's not just after a story—he's after Ellie herself—there's no changing his mind. There can be no mistaking it: He's hooked, and even though he continues to fight with Ellie almost until the end of the film (in fact, the last time we see them together, they're still fighting), we learn to recognize this squabbling as an expression of love.
Not that fighting's the only thing that Peter and Ellie do together, of course. On the contrary, It Happened One Night shows them sharing all kinds of adventures—which is just what Peter wants. When Ellie asks him what he's looking for in a woman, he answers,
PETER: She'd have to be the sort of a girl who'd jump in the surf with me on moonlit nights—and love it as much as I did.
As the film nears its end, Peter realizes—later than Ellie does—that this is just what she has been doing with him all along: jumping right into adventure after adventure. And this, together with the je ne sais quoi that is their chemistry, is why he loves her. Luckily for Peter, he's chosen a leading lady who's adventurous to the end—one who's willing to leave the man she's already married at the altar, seek an annulment, and make the transition to wedded bliss, campground-style.
Peter Warne's Timeline