Why have Maus I and Maus 2 both become such huge blockbusters? Which one is more successful and why?

Maus I and Maus II are blockbusters, and they have been read widely and assigned in school curricula across the world. Their success is a result of many factors, including the way in which Spiegelman decided to tell the story through the use of animal characters and a graphic novel format. He was one of the pioneers of using the graphic novel to tell a serious story. The animal characters allow readers of all ages to better relate to the story, and they also provide an immediate graphic impact, as the reader can see right away who is German, Jewish, American, or Polish. In addition, Spiegelman turns the idea that there are certain "races" in Nazi ideology on its head by making animals represent these supposed races. His take on the Holocaust is filled with bitter irony as well as pathos. He inserts himself into the narrative and finds out about his family's history at the same time the reader is finding out about it, making the story more immediate and forceful.
Maus I might be considered more successful, as it was groundbreaking in its content and format. In 1992, after the second volume was published, Maus won a special award and citation by the Pulitzer Prize committee. Maus I was one of the first graphic novels to receive critical awards. The first volume of the book also broke barriers in Germany, which allowed the book to be published with a swastika on its cover (which is against the law in that country). Both volumes have been translated into many languages and used in schools around the world; however, Maus I was the book that initially broke barriers and thrust Spiegelman and his family's story into the world's spotlight.