The history of the epistolary novel is quite rich. In the 18th century, it reached new heights with works like Richardson's 'Pamela' and 'Clarissa'. These novels used the letter - writing format to tell complex stories of love, morality, and society. The form was appealing because it made readers feel like they were eavesdropping on the characters' private lives. It also allowed for multiple viewpoints as different characters could write their own letters.