The Selection

The Selection is a young adult novel by Kiera Cass first published on April 14, 2012 by HarperCollins. It is the first in a five-book series, followed by The Elite (2013), The One (2014) and The Heir (2015) and The Crown (May 2016). The last two take place twenty and twenty-five years after the events in the first three.
In addition, four spin-off novellas were released. The first two, The Prince and The Guard, are narrated from the point of view of two supporting characters. The Queen and The Favorite are prequels, focusing on two other supporting characters in the main series. All four novels were collected into one volume Happily Ever After, including bonus content and epilogues.
Cass stated that she began writing The Selection after thinking about the differences between Esther and Cinderella, wondering if either of them were happy with how they ended up. She also commented that she had written the book "from start to finish", while her writing process for the other books differed.

Summary

In a dystopian fairy-tale world where society is divided into castes. Ones are the most prosperous, consisting of royals and elites. Eights which are mostly orphans, drug users, handicapped, and unemployable. America is a Five, the "artist" caste (e.g. musicians, artists, actors, dancers, etc.), but since their prosperity depends on their desirability, Fives live a lower class life. America, however, doesn't care, because she loves entertaining, especially with a violin. The prince of Illéa, Maxon Schreave, announces that he is following his father's footsteps by holding the Selection, a competition for the prince's hand and a crown. Despite pressure from her mother, America has no interest in entering the competition, because she already has Aspen, her secret boyfriend that she's in love with.
America decides to have a surprise dinner at the tree house with Aspen. Instead of being happy, Aspen is upset because he believes he should be the one to provide for her, but is unable to because he is a Six (the servant caste) and has no means of providing for her since he already has to take care of his mother and siblings. In the end, Aspen decides to break up with America. The end of their relationship, plus a bribe from her mother, leads America to enter the Selection and later into the palace where she has to compete with thirty-four other girls to win the prince's heart. It also helps that her time in the palace is accompanied by a small stipend sent to her family.
America easily makes friends (Marlee Tames) and enemies (Celeste Newsome) within the first week of her stay, but her unique personality also catches the attention of the palace staff and the country. However, she still doesn't want to marry Prince Maxon, but a chance meeting in the gardens causes them to befriend each other. America still loves Aspen, but she gradually starts to fall in love with the prince who is nothing like what she imagined. It doesn't help that Maxon gives America his first kiss, and she begins to think that she could maybe marry him and forget Aspen. It also doesn't help that rebels constantly attack the palace, which helps turn away the weak-hearted competitors, but also makes things tense, especially when the rebels seem to be getting closer. Things also become tense in the competition when America starts to feel jealous of Maxon spending time with the other Selected.
America eventually sees Aspen again when he enters the palace as a new member of the guard. He was apparently drafted into the army where he earned top honors. Aspen's appearance confuses America's feelings even more and she begins to feel like she is still in love with him when he sneaks into her room to see her. Having any kind of romantic relationship with someone other than the prince during the competition is considered treason, and the punishment for treason can be as severe as death. Despite knowing the consequence, America can't help but be with Aspen.
After another attack from the rebels that leads to three of the Selected leaving, Prince Maxon decides that he will narrow down the girls from ten to six, calling them The Elite. When America's name ends up amongst the six chosen to stay, she is surprised how relieved she feels and realizes that she does have feelings for Maxon and could see herself happy with him. With this in mind, she tells Aspen that she cannot continue their romantic liaisons. Instead of getting discouraged, Aspen claims that he will fight even harder to win her love again over Maxon. The book ends with America finally realizing that she is exactly where she ought to be — among The Elite.