When the first Hispanic pope arrives in the United States on September 22, he will be greeted by an increasingly Hispanic and Asian-American Catholic population.

The majority of the nearly 70 million U.S. Catholic congregation (59 percent) is still non-Hispanic white. However, this percentage has been steadily declining because many in this population are elderly and fewer young people are participating in the church.

In contrast, approximately 55 percent of U.S. Catholics under the age of 30 are Hispanic.

The shift in demographics is bringing many changes to American churches. For example, at St. Helena Church in north Philadelphia, founded by German and Irish immigrants, the congregation is now mostly from places like Vietnam, Ecuador and the Philippines. Their thriving participation is helping to preserve the 100-year-old building.

“We go to Mass that’s Spanish or Vietnamese, and because our Mass is so structured, we can follow it and know what’s happening. It doesn’t have to be in our language,” one parishioner told National Public Radio. “Basically we can pray together, no matter what language we use.”

Catholic students pray the rosary at a church in Kansas. About 55 percent of U.S. Catholics under the age of 30 is Hispanic. (© AP Images)

In Bensalem, Pennsylvania, St. Charles Borromeo Roman Catholic Church, built by Irish Catholics in 1903, has merged with the nearby Hispanic parish Our Lady of Fatima. Now, Mass is celebrated in Spanish as well as in English.

One veteran parishioner told CNN, “We’re white, middle-class Americans. It’s nice to realize that we’re part of a universal church. … This gives you that sense of belonging. It gives you a sense of belonging to the church in the world.”

The trend is happening across America. More than 30 percent of U.S. parishes are shared between at least two ethnic or racial groups, with English and Spanish as the two most common languages.

But it is worth remembering that the first Catholic parish in what is now U.S. territory was Hispanic. The first church was built in San Juan, Puerto Rico, in 1521, and the oldest Catholic mission was established in 1566 in St. Augustine, Florida. So Hispanic parishes have been part of U.S. Catholic tradition from the beginning.