Irish and English immigrants brough the tradition of Halloween to America during the wave of immigration in the mid 1800s.
Mexicans do not celebrate death on the day someone dies. Instead, they celebrate death on the Day of the Dead.
Halloween culture can be tracked back to Mexican culture. The Mexicans made Halloween what it is today by celebrating the day of the dead on October 31st.
Mexico
You can celebrate Easter and Christmas.
Kids wear costumes and ask for candy in their neighborhoods. The main difference is that instead of saying "trick or treat" when asking for candy they say "Halloween, Halloween."
Sorry, I should have said Latin Americans....please pardon any offense to Mexicans
Mexicans in Mexico do not celebrate Easter by making Easter eggs. Instead they take a vacation and attend mass and even have a recreation of the "Way of the Cross."
Mexicans, and other speakers of the Spanish language, call Christmas, Navidad. Instead of Merry Christmas, they say Feliz Navidad, which means "Happy Birthday."
Yes, Pinkie Pie did dress up as a chicken for Nightmare Night. (In Equestria, they have Nightmare Night instead of Halloween.)
The majority of Mexicans are Roman Catholics and do not believe the souls of people come back as anything, but instead go to Heaven or Hell, or Purgatory.
In the Netherlands they don't really celebrate Halloween but instead the religious holiday Saint Martins. It is similar to Halloween because the children go door-to-door wearing masks to get candy, but instead of saying "trick-or-treat" they sing. Saint Martins is celebrated on November 11 and has nothing to do with anything scary or horrifying.