The Earl's Defiant Wallflower

A rags-to-riches, forbidden love, opposites attract romance from a New York Times bestselling author:
Oliver York returns from war to find his father dead, his finances in arrears, and himself the new Earl of Carlisle. If he doesn't marry an heiress-and fast!-he and his tenants are going to be pitching tents down by the Thames. He definitely shouldn't be trading kisses with a penniless debutante... no matter how captivating she is!
Miss Grace Halton is in England just long enough to satisfy the terms of her dowry. But a marriage of convenience isn't as easy as she'd hoped. Back in America, her ailing mother needs medicine only Grace's dowry can afford. Which means the dashing earl she can't get out of her mind is the one man she can't let into her heart.
The fan-favorite Dukes of War series features roguish peers and dashing war heroes who return from battle only to be thrust into the splendor and madness of Regency England.