The term “trick or treat” dates back to 1927.
The earliest known reference to “trick or treat”, printed in the November 4, 1927 edition of the Blackie, Alberta Canada Herald, talks of this,
Hallowe’en provided an opportunity for real strenuous fun. No real damage was done except to the temper of some who had to hunt for wagon wheels, gates, wagons, barrels, etc., much of which decorated the front street. The youthful tormentors were at back door and front demanding edible plunder by the word “trick or treat” to which the inmates gladly responded and sent the robbers away rejoicing.
The British hate Halloween, apparently. In 2006, a survey found that over half of British homeowners turn off their lights and pretend not to be home on Halloween. Yet another reason by the United States is happy to be free from British rule. No funs. More at SmithsonianMag.com