The series is The Selection by Kiera Cass. It is the story of America in the future where the country is divided by castes and ruled by a King and Queen. Not everyone is happy about the caste system and one of the ways that the monarchy tries to keep everyone working together is to have the next King choose his Queen through a selection. Thirty-five young women from all over the country and from castes from two through eight are brought to the palace to meet the prince in hopes of winning his heart. But, the selection is full of drama as a young woman with strong opinions and not many romantic intentions catches the Prince's eye. Talk about a way to shake up the kingdom.
If you enjoy a quick read that deals with social issues in a fun way, you might enjoy this series as much as I have.