A look at the history of Cathedral Basilica of Saints Peter and Paul

LOGAN SQUARE (WPVI) -- When Pope Francis celebrates mass at the Cathedral Basilica of Saints Peter and Paul in September, it will be just the latest significant chapter in this cathedral's rich history.

"The Basilica will be full. We'll use every inch of space," said Reverend Dennis Gill, pastor and rector of the cathedral parish.

The mother church of the Archdiocese of Philadelphia opened in 1864 on the East side of Logan Square. At the time, Abraham Lincoln was president.

"This location may not have been considered the prime location that it is today, just a little outside the center of town," said Rev. Gill.

The dome identifies the building from afar. Four massive Corinthian columns are positioned at the facade.

This is the largest brownstone structure in Philadelphia. The stone originally came from quarries in Connecticut and New Jersey, and while it's had to be repaired over the years, it has become a distinctive feature.

"It wasn't a period of great affluence for the church in the City of Philadelphia so at the time it was not considered the most expensive stone to be used," said Rev. Gill.

While the pope's visit is being widely celebrated, at the time this cathedral was built an anti-Catholic sentiment existed in the city. And that was taken into account in some of the architectural features.

At a time when Catholic churches were being burned in riots, only some very high clerestory windows were built to prevent vandalism.

"In fact there's a story that the bishop at the time or the contractors at the time would have people throw rocks as high as they could to see where the windows should go," said Rev. Gill.

The stained glass windows behind the altar were added in a major renovation in the 1950s.

The interior is spacious, ornate, with bronze chandeliers, and a floor of marble tile.

The organ is one of the largest in the city.

And while only so many people can fit inside when the pope offers mass, this church is special for Catholics and non-Catholics alike.

"Everyone is welcome here, everyone has a home here," said Rev. Gill.