Here are some well researched articles about the origins and non-origins of American Halloween from John Sanidopoulos:
The Media killed Halloween.
Covid1984; nailed Halloween’s coffin shut.
But, every crisis is an opportunity:
Halloween’s silvery moon;
has moved away,
from those door to door neighborhoods;
to those new bazaars,
called commercial malls -
under the heavy-duty spell of fluorescent lights,
being mauled to death.
All Saints’ Day (Latin: Sollemnitas Omnium Sanctorum) — a Catholic holiday according to the calendar of the Roman Catholic Church, and it celebrates all the saints, both those who have already been canonized and those who have not yet been canonized. All Saints’ Day is celebrated on November 1.
In Orthodox churches, this holiday is marked on All Souls’ Day and marks the end of the Easter part of the liturgical year.
This holiday dates back to the 4th century. The first traces of a general celebration of all the saints were observed first in Antioch, on Epiphany. This custom is recorded in 74 homilies of St. John Chrysostom (407) and has been preserved in the Eastern Orthodox Churches to this day.
Pope Gregory III (731 - 741) moved this holiday to November 1 so that it could coincide with the ancient Celtic festival of Savin (Irish: Samhain) which marked the beginning of the New Year. In this way he responded to the demands of the Irish monks.
In the time of Charlemagne, this holiday was already more widely celebrated, and King Louis the Pious in 835 declared it a public holiday. The decision was made at "the request of Pope Gregory IV with the consent of all the bishops.
I hope some of you notice the difference in the wording of the name of the holiday.
There is a significant difference in naming, and all saints is not the same as all souls.
All saints in my humble opinion means all individuals within the Christian religion, while all souls means all, well all souls regardless of whether they are canonized as something special holy or not!