Waiting for a Rogue by Marie Tremayne

Lady Caroline Rowe is determined never to marry. After the disastrous end to her last Season, she wants nothing more than to live quietly with her aunt in the country. But her resistance starts to slip when an exasperating new neighbor, The American, begins to invade not just her land, but her life. And, of course, he is the last man who should ever tempt her…
Inheriting an estate across the Atlantic has proven more difficult than Jonathan Cartwick ever expected. Avoiding his infuriating neighbor is tougher still, especially once he finds himself drawn to the ravishing beauty. Living a life he never wanted has been hard enough, but soon he fears losing his sanity, and his heart, to Lady Caroline…
When Caroline’s parents threaten to marry her off to the first lord who will take her, she is devastated. And against all odds, Jonathan finds himself wanting to prove to the troublesome minx that he might just be the man she has been waiting for.