The Catholic Church has had 17 popes since the United States was founded 239 years ago. But only three traveled across the Atlantic from Vatican City for a visit. That will change Tuesday when Pope Francis arrives in Washington for a six-day U.S. visit, which includes stops in New York and Philadelphia.

The pope leads the world's largest Christian church -- with 1.2 billion members -- so his visits overseas are a big deal. He usually meets heads of government. In Washington, Francis will be welcomed by the president and first lady -- just the third time a pope has visited the White House — and he will address Congress, which is a first!

Francis is very familiar with firsts. He is the first pope from the Americas, having been born in Argentina. And he is the first to take the name Francis. He's the first from the order of priests called Jesuits. And -- good trivia question -- he's the first with just one lung, having lost the other to infection while a teenager.

Though he could live in a palace, Francis prefers a simple lifestyle. His home is a modest apartment. He loves soccer and a dance called the tango. In his pre-pope life, as a cardinal in Argentina, he cooked for himself and rode city buses. Don't expect to see him riding Metro in Washington, however. He will ride in a "popemobile," a white Jeep that is being watched over by the Secret Service.

We asked Cardinal Donald Wuerl, the leader of the Archdiocese of Washington, some questions about Francis's message for young people.

Q: Why are people so excited about this visit, and what about it is special for children?

A: In Philadelphia, the pope will greet people attending the World Meeting of Families. That is where we can best understand his visit in terms of family. The pope has a message for all of us: It is the message of Jesus, who tells us of a wonderful way of life where we each care for one another.

All of us know how important our family at home is to us. We grow up surrounded by the love and nurturing of family members. . . . Pope Francis will remind us that we are also part of the great human family, God's family. . . . We are God's children and therefore brothers and sisters to each other. Family members care for one another, they are nice to each other, they share and help each other.

Q: Is there a role for children in some of the issues important to Pope Francis, such as climate change and family life?

A: Children will be very much in the forefront during the pope's visit. He brings a message of love and care for everyone . . . and the things God made for us, such as the Earth. We need to take good care of it for others to enjoy after us.

Children can [support] the pope by doing good deeds for those less fortunate. . . . In caring for the Earth, the common home of all humanity, young people can begin by taking care of their family home: keeping their room clean, recycling and not wasting food or electricity. In this way, you learn to care for the environment, too.

Q: Since the pope is head of the Catholic Church, is his message just for Catholic children?

A: The title "pope" means "papa," so Pope Francis is like a father or grandfather to us all. He will be reaching out to all children to tell them how much God loves them.

Q: The pope's popularity worldwide has some writers comparing him to a rock star. Have you met him? What's he like?

A: I have met him several times. In pictures, he is smiling and shows a kind and friendly face. That is exactly how he is in real life. You can see the love of God at work in him and his wish simply to share that love with everyone. If you have a chance to meet him, I know you will like him. He will also like you.

Q: Is there anything you would like to add about Pope Francis and his message for children?

A: It is very important that children know that you have the chance to make this world a better place. It begins with taking time each day to say a prayer, to let God know that you want to be his friend, and then doing something kind and helpful for your family, your schoolmates and friends.