Why isn't Halloween a holiday?

because its not the true reloign of the united states

I am a different person than who wrote the above:

This is not true- it is technically an unofficial holiday. The United States does not have a specific denomination of religion.

Hallowe'en/All Hallows Eve:

From Fisheaters.com:

31 October:

Hallowe'en:

"unofficially recalls the souls of the damned. Practices center around the reality of Hell and how to avoid it. "

It is not an unofficial holiday, there is no such thing as an unofficial holiday, Towns/Counties/States etc.. can proclaim certain days holidays but until they do it is just a day with a name nothing more.

As for the question, it is because Halloween is a sacred Wicca (witch craft) day, the United States does not have a "true religion" however all of its laws and customs are based (notice I say "based") on Christianity and would cause an unbelievable amount of controversy over an "official" holiday for a Pagan (devil worship) day.