Crescent City, by Belva Plain

Historical fiction/romance set in New Orleans, Louisiana and a plantation near New Orleans prior to and during the American Civil War.
Miriam's mother had been brutally attacked in a pogrom against Jewish villagers in a small German town, and tragically died moments after Miriam's birth. Her father left shortly afterward to make his fortune in America, leaving Miriam and her brother David with their grandfather and spinster aunt. Years later, he returned and took the children to his grand home in New Orleans. At the age of 16, as was the custom at that time, Miriam was given in marriage to Eugene, a man at least ten years older. Miriam and Eugene doted on their twins, a son and a daughter, but there was no love, no joy between them. They lived separate lives in the same house, even in the same bedroom.
These were perilous times; abolitionist feelings against the "peculiar institution" of slavery were mounting, and soon the storm of Civil War broke loose. There was a storm in Miriam's heart as well, as she dealt with guilt, loss, tragedy, and heartbreak.