Why is the adventures of huckleberry finn considered an example of realism

As children, most of us can remember reading fantastical stories about larger-than-life heroes who swoop in to save the day, sometimes through the use of magical powers or forces, and often ending with all of the good characters living happily ever after. For a long time, romantic stories like these were common among writers because they captured their reader's imaginations with elaborate tales that couldn't be found in real life. However, in America around the time of the Civil War, big changes for the country also meant big changes in literature. With huge increases in immigration, technological developments, and war on the horizon, writers began to shift their focus from romantic depictions of life to stories that more accurately represented life as it really was. Writing in a style known as realism, authors like Mark Twain now included real-world settings that actually existed or could exist, used realistic characters that could be compared to everyday, average people in America, and presented societal issues that those people really struggled with. In his novel The Adventures of Huckleberry Finn, Twain uses several elements of realism to tell his tale. 

he gives his freedom of speach

explanation:

expository writing is one of the most common types of writing.