Halloween was brought by settlers to the new world. In the United States have been adding various elements can be said to "scary" as - monsters, skeletons, ghosts, and other stuff.

The date, but was placed by the fact of something being a"persecution of witches" so the name Halloween - Halloween.
The symbols of Halloween are black cats, witches, pumpkins, candles, witches, broom, apple, bat and others.