Master of Paradise by Virginia Henley

When Nicholas Peacock is cheated from his inheritance of Peacock Hall in Kent, he sails to South Carolina. He buys land, clears it, and plants cotton. Eventually he builds a magnificent house known as Paradise Plantation. He falls in love with the daughter of Bernard Jackson on the neighboring plantation, but when Civil War threatens circumstances force him to agree to a marriage in name only. The sexual tension is stretched to breaking point as the would-be lovers are torn between honor or surrendering to the love and longing in their hearts.