Not all were pleased with the increased security.
"They put up a Berlin Wall between us and the pope and we couldn't get anywhere near him. You could tell he wanted to get close to us but the police really insisted on this separation," said Joao Franklin, a 51-year-old from Minas Gerais state. "I felt really excluded by all these barriers and don't see the need for them. We're all here to show our love for him and we just want to get close to show him that love."
Nacilda de Oliveira Silva, a short 61-year-old maid, perched at the front of the crowd though she was barely tall enough to see over the metal barrier.
"I have been up for almost 24 hours, most of that time on my feet and in the rain and the cold. But I don't feel any pain. I feel bathed in God's glory, and that's because of the pope. For me, it's the same thing as seeing Jesus pass by. That's how moved I feel."
Before the Mass, some pilgrims sought shelter from the Southern Hemisphere winter chill beneath tarps while others wrapped themselves in blankets and sleeping bags. And many left offerings to the Virgin.
Lena Halfeld, a 65-year-old housewife, paused to add her offering to a cardboard box filled with stuffed animals, leg braces and other personal objects. She deposited an embossed invitation to her niece's December wedding, which she was praying for the Virgin to bless.
"I have real faith in the powers of the Virgin of Aparecida," said Halfeld, adding she had made the hours-long trip to the church once a week for a year during her husband's recent illness. "Now he's cured, so I owe it all to her. I can't think of a more wonderful setting to see the new pope."
Francis is in Brazil for World Youth Day, a church event that brings together young Catholics from around the world roughly every three years. Approximately 350,000 young pilgrims signed up to officially take part in the Youth Day events.
In Aparecida, 16-year-old Natalia Pereira, a high school student from Sao Paulo state, said the cold rain she endured to get to the basilica was a "test of faith."
"I've been up all night in line, I'm soaked to the bone and freezing but I'm so excited that it's worth it," said Pereira, who tried to huddle from the drizzle beneath a friend's large umbrella. "This is my first time seeing a pope and this was an opportunity of a lifetime for me. I wasn't about to let it go because of a little rain."