If this novel belongs in the canon of American literary classics, the novel would qualify for two reasons.
First, this is a book chronicling an important period in American history wherein the values at the core of the "American democratic project" were tested and proven. As a novel concerning civil rights and progress toward social integration among races in America, this novel relates to issues that are of great importance to the social-national identity of the country.
The main theme of the book is racial prejudice and bigotry—hate directed toward blacks in respect to their race.
The quality of the novel would be a second qualification. The most outstanding stylistic achievements of the novel relate to Stockett's successful rendering of suspense, use of symbolism, and articulation of multiple narrative voices.
However, many critics will point to a marked similarity between the voices of Minny and Aibileen (and also point to the odd choice to use dialect in the presentation of the African American narrators while using no dialect when presenting the narrative of the Caucasian narrator).
The novel certainly demonstrates a narrative profiency, presents clear character motivations, and constructs a compelling plot. Stockett's achievement with this novel is considerable, especially considering the expertise she presents in the construction of narrative suspense and tension.
The novel does not break any stylistic ground, however, does not comprise an expression of original artistic vision, does not articulate any new ideas or insights regarding the historical period it examines, and does not consistently adhere in its choices to the political and social values it espouses.
The canon of American literary classics is characterized largely by stylistic breakthroughs as in the masterpieces of Faulkner and Hemingway. These works also demonstrate an artistic vision that is rather perfectly married to the style of the work.
Placing Stockett's novel in the same category as "The Wasteland" and the great works of Arthur Miller is, ultimately, a subjective decision. We might be helped in making this decision by looking at the works already in the American literary canon that are most closely related to The Help.
The works that might best be compared to Stockett's novel are written by African Americans. This is true due to the themes of her novel, which, as stated, constitutes the first reason her work might belong in the canon of American literature. Other highly regarded literary works dealing with social integration and civil rights in America include The Invisible Man, Native Son, and A Raisin in the Sun.
These works are often regarded as literary masterpieces in their own right and they also deal with important American value issues. If we can say this is true of Stockett's novel as well, we can argue The Help should be included in the American literary canon.
Ultimately, canons are a subjective exercise. While Stockett's achievement with this novel is clear, the place of the novel in the American canon is not entirely clear.
It has been favored by the critics as a highly readable and accurate portrayal of life in Jackson, Mississippi during the early civil rights movement.
It may be important to note here that books can be significant and good without being "great" and without being considered "literary masterpieces".