what is the history of Halloween ?

[Sepehr]

does it have a history event or something or people just celebrate it for fun ?

 

[Soylent]

There's no quick answer to this, best bet is to read the wikipedia page on it.

'"Halloween has origins in the ancient Celtic festival known as Samhain (Irish pronunciation: ['s?aun?]; from the Old Irish samain, apparently derived from Gaulish samonios). The festival of Samhain is a celebration of the end of the harvest season in Brythonic and Gaelic culture, and is sometimes regarded as the "Celtic New Year". Traditionally, the festival was a time used by the ancient Celtic pagans to take stock of supplies and slaughter livestock for winter stores. The ancient Celts believed that on October 31, now known as Halloween, the boundary between the living and the deceased dissolved, and the dead become dangerous for the living by causing problems such as sickness or damaged crops. The festivals would frequently involve bonfires, into which the bones of slaughtered livestock were thrown. Costumes and masks were also worn at the festivals in an attempt to copy the evil spirits or placate them.'

 

[Hh F]

I love this question!,
Thousands of years ago they had i night were spirits arose for one night,
Hallows eve on that night they believed that three witches stood round a stone table while there sister was giving birth,
Although there sister was mortal they loved her so,
When she gave birth to a Beautiful young boy something happened,
She got struck by a giant force making her son and her share the powers that embedded the child,
This field spread across the world making havoc turning people into jackalantern creatures into not magical witches and skeletons and into baby grim reapers,
Suddenly the baby disappeared into the sky and was never seen again by anyone but 12 years later the mother felt something,
In her chest and then,
Her child returned from the ground and they changed the name to halloween.

That's why people dress up and that's why it's very celebrated.