Our Lady of Guadalupe is Mexico's representation of the Virgin Mary. Followers turn to her in times of crisis.
The shrine in Des Plaines hosts the biggest gathering of its kind outside of Mexico every year.
Over the weekend, the festivities were already underway, when over 950 horseback riders rode from Northbrook to the shrine in Des Plaines as a sign of devotion and respect. The feast of Our Lady of Guadalupe is a Catholic holiday that celebrates the Virgin Mary.
On Wednesday evening, those celebrations will officially begin, with an opening Mass at 8 p.m. Fireworks will follow.
And then the next day, on Thursday, it will mostly be a full day of prayer before the closing Mass in the evening.
Church leaders are also preparing for frigid temperatures.
But, the cold doesn't seem to deter people.
Although, those who came Monday were happy they only had to endure 50-degree weather.
There's already been a steady stream of people coming to pray and show their devotion.
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The shrine is already surrounded by flowers. Three hundred thousand people are expected to make the pilgrimage Wednesday and Thursday.
"Whatever it is that they're going through, that's far more intense than any temperature we can throw at them," the Rev. Esequiel Sanchez said.
Sanchez knows the pilgrimage for many won't be easy. He said people will come from Washington and California to Texas and New York.
"What trumps the cold for us is what's going on in them, what's going on in their heart. So, if they're coming to this, you know, 20-degree temperature here, that must be something a lot more intense going on in the heart than just temperature concerning them. And that's the miracle you get to see," Sanchez said.
While there is a warming center on-site, those making the journey are told to come prepared, travel with a group, know their routes and wear plenty of layers. Many will walk miles, some on their knees, to pray to Our Lady of Guadalupes.
"I come here every week since I was diagnosed with bladder cancer five years ago. So, I have never missed a week. I pray to her all the time, and I feel like she gives me strength," Chicagoan Mary Capello said.
Families, young and old, attend. Some are passing on traditions from one generation to the next. Mundelein resident Amy Silva said her faith started with her grandmother, and now she's sharing it with her babies.
"More than anything, I want to say, 'thank you' to her because I just had my newborn, and it was very important to me because I know she was there with me," Silva said.
Sanchez is also making it clear that all are welcome this week.
He said there will be significant security, but that police are simply there to help with the considerable traffic impact and to keep people safe.