The literary canon, a historical body of masterpieces and classics, is considered the best of the best; literary works that withstood the test of time. Many of the authors whose works have been included in the canon are white males like William Shakespeare and Mark Twain. The general exclusion of women and other races often means the merit of their works are overlooked and dismissed.
Because of the different views of the time, one would expect a variety of opinions reflected in the writing of the time, however because the canon is primarily white males it is limited to a small portion of the population. The rest of the population "women, blacks, Hispanics, those of Oriental descent and other "are excluded and their opinions are often overlooked. Until recently, Kate Chopin has been excluded from the canon so her masterpiece, The Awakening has been ignored. The tales of slavery written by former slaves or children of former slaves also have been excluded.
The fact that the canon only has books older than a hundred years included in it mean that modern works are sometimes ignored, so the canon also makes people consider the view of older times and we are constantly looking back. Many of the views of other times are outdated in the modern society, but because they are part of the literary canon and often taught in school, means that the future generations must read them and can be swayed, unintentionally, to believe that women are insignificant and weak or that blacks are stupid and bestial, causing sexism and racism in a society that is trying to do away with that.
The canon is narrow, meaning there are few works included in it. Those works area supposed to be wonderful, and because they are segregated from the general riffraff' of literature they gain a kind of glory. Also they appear to be more unique than the rest, because they are more read they are familiar, and if someone who's read the canon reads a similar non-canon book, the non-canon is frowned upon for being like the canon.