Jacob Have I Loved is the tale of Louise and her twin sister, Caroline. Although Louise is older by a few minutes, her sister Caroline is the favored child. Her birth was filled with drama and even as a baby, Louise was often ignored. When an old sea captain returns to his home on their small island, Louise's life is turned upside-down with boys (and men), her sister, and the cruel taunts of her grandmother.
Louise had always felt out of place on the island, where "men's work" and "women's work" are strictly divided. Louise loves the sea and wishes to become a fisherman like her father, but, unfortunately, that is considered man's work and not appropriate in their tiny, isolated, strictly-Methodist town.
When Captain Hiram Wallace returns to his birthplace on Rass Island, Louise at first hates him for stealing her best friend, Call, but later develops a crush on him. Her grandmother taunts her cruelly and unmercifully. Even worse, when the Captain's wife dies, Louise's grandmother accuses her of using rat poison to murder the old woman.
A little bit on this grandmother: I'll just tell you now, you wouldn't want her anywhere near you. When she finds something wrong with a person, or something that she doesn't approve of, she insults and taunts them with biblical verses. One day, she reads her own granddaughter the verse "Jacob have I loved,but Esau have I hated", referring to the brothers Jacob and Esau (correct me if I'm wrong, this is all coming from the book as I've never read the Bible). Supposedly, God himself said this, Jacob being the younger brother and Esau being the older one. She also accuses the Captain of some much worse things, and Louise's mother also.
The Jacob Have I Loved taunt sends Louise into a deep depression and she begins to believe that God himself hates her. When her friend Call is sent away to war, she begins to help her father on his boat, although it is disapproved of. She drops out of school and begins being home schooled by her mother and the Captain.
When the Captain offers to use the money from his dead wife's will to send Caroline (Louise's sister) to a special boarding school in New York, where she could develop her talent for singing, Louise becomes even more depressed.
However, when her parents return from (Spoiler alert!) Caroline and Call's wedding, her mother tells Louise that they really always loved Louise very much. The Captain tells her that she is smart enough to do anything she wants in life. She realizes that she dreams of becoming a doctor (What?! I had no idea that this was coming. There were no hints of it earlier on.) and asks her mother if she could go to a college. Her mother promises to not prevent her from leaving and Louise receives a scholarship to become a doctor. However, she is prevented from continuing in the course (Because she's a girl- this took place around the time of Franklin D. Roosevelt) and advised to train to be a nurse or midwife instead.
She leaves to the mountains and lives in a small valley with very few people and becomes a nurse and midwife. She meets a man she loves, marries, and gets her sort-of happily ever after.