Hawthorne wrote in a period of unrest in the United States. France was undergoing a bloody revolution calling for much change between the ruling power and the struggling middle class. Americans were growing divided about their views of slavery, and the transcendental movement was underway among authors.
Hawthorne had his name to defend (the Salem Witch Trials occured through his lineage), and perhaps a variety of messages to society. This mid-nineteenth century work was written set in the mid-seventeenth century to separate the messages he would share from the context of the novel. He may have had some direct messages that would have hurt had he used a modern day setting.
Pearl's character certainly takes an identity of its own that separates itself from Hester. Pearl is referenced as the "Devil child" and a demon. This is the complete opposite of the Purtian wish for children. Hawthorne uses Pearl's character to portray a new identitiy separate from the identity of the past. Having her maintain her childhood character for the majority of the story, we see the innocence and the limited knowledge a new generation has. Any new generation can only deal with the information put in front of them. Hester shields Pearl from the truth of their situation for the majority of the book. This is so important because Pearl wants Hester's letter to remain on her because it is what Pearl has grown accustomed to. However, what it stands for is something Hester eventually wants to leave behind. But Pearl, being a child, is particularly comfortable with keeping the letter on her mother.
Furthermore, being born on American soil distinguishes her from the life her mother may have lived in England, but the fact that Pearl eventually goes back to Europe and presumably stays there demonstrates that what we try to teach upcoming generations doesn't necessarily always stick.
Pearl is a symbol of change, but change isn't always positive. She is perhaps a symbol of transforming tradition. Sometimes the new is ugly and difficult to deal with even when we try to make it fit our situations. In Hawthorne's time, he correctly prophesied that the state of the United States would need to get worse before it got hetter. The impending Civil War was evidence of that as it occured a few short years after his writing.