By the 11th century, this had been adapted by the Church into a tradition called souling, which is seen as being the origin of trick-or-treating. Children go door-to-door, asking for soul cakes in exchange for praying for the souls of friends and relatives.
By the 1920s pumpkin carving was widespread across America, and Halloween was a big holiday with dressing up and trick-or-treating.
The Americanised (Americanized?) Halloween that we experience today actually originated in the Celtic fringes of Britain, and was adapted over the decades by Christian traditions, immigrants conventions and an insatiable desire for sweets.