History in the USA

Halloween's origins trace back to the ancient Celtic festival of Samhain. It was brought to America primarily by Irish and Scottish immigrants in the 19th century. Early American celebrations were a mix of public harvest festivals and private parties. The modern practice of organized, widespread trick-or-treating—as a way to curb destructive pranks that had become common—didn't truly become a national tradition until the 1930s to 1950s.