Halloween actually has its origins in the Catholic Church. It comes from a contracted corruption of All Hallows Eve. November 1 st, All Hallows Day (or All Saints Day) is a Catholic day of observance in honor of saints.
In Mexico, they celebrate El Dia de los Muertos or the Day of the Dead starting the evening of October 31 st.
The custom of Halloween was brought to America in the 1840s by Irish immigrants fleeing their countrys potato famine.
On November 2 nd, All Souls Day, early Christians would walk from village to village begging for soul cakes. This is one origin of trick- or-treating.
The Celtic festival of Samhain is the basis for Halloween. Samhain, All Hallowtide, the feast of the dead in Pagan and Christian times, signalizing the close of harvest and the initiation of the winter season.
The day itself did not grow out of evil practices. It grew out of the rituals of the Celts celebrating a new year, and out of Medieval prayer rituals of Europeans.
In the 1800s, people started to have Halloween parties. Part of the celebrations included costumes, fortune telling, and games such as bobbing for apples.
At the turn of the century, cities were overcrowded and Halloween marked the time to let off steam by playing practical jokes. By the 1930s, things had gotten out of hand and serious damage was being done on Halloween. Trick or treating was promoted as an alternative to vandalism.
The Celts believed the souls of the dead visited the earth every October 31 st.