Halloween:D

Halloween originated from the Celtic
(irish, scottish, welsh, Cornish and manx)
holiday oiche shamhma
(irish for halloween)
that was predominantly celebrated in ireland. It was brought to America as irish culture during the famine, where Americans accepted the culture and brought it into their own.
They spread it and now a tradition that started in ireland and spread through other Celtics countries is one of the main holidays in the world :3