Pope kicks off historic day in D.C. with speech, parade

Pope Francis got a thunderous welcome Tuesday afternoon when he arrived at Joint Base Andrews, just east of Washington, for his first-ever visit to the United States. In a rare honor, President Obama and his family were there to greet him, along with the Bidens and 1,000 onlookers chanting, "Welcome to the USA."

The Holy Father met privately with the president before leaving the airport in a modest Fiat, all smiles through the open windows. He was greeted by more crowds when he arrived at the Nunciature, his home for the next two days.

But the official red carpet will be rolled out this morning, as the pontiff kicks off the events of his five-day visit, reports CBS News correspondent Jan Crawford.

Pope Francis hits controversial topics during first morning in U.S.

More than 15,000 people are gathered at the White House South Lawn Wednesday morning to hear him speak at his first event. People began lining up as early as 4:00 in the morning when the gates opened.

At 9:00 am President Obama will welcome the Holy Father to the White House South Lawn, where more than 15,000 invited guests will hear the Argentinian-born pontiff deliver his first address in the U.S.

At 11:00 am, the pope hops in his popemobile for a short parade. Tens of thousands are expected to gather, hoping for a glimpse.

A half hour later, the pope will lead midday prayer with U.S. bishops at St Matthew's Cathedral.

And at 4:15 pm, he will head to the Basilica of the National Shrine of the Immaculate Conception, the largest Roman Catholic church in North America, to celebrate his first Mass. He is the third pope to visit the Basilica on the Catholic University of America Campus, reports CBS News correspondent Chip Reid.

Tens of thousands expected at Pope Francis' first U.S. Mass

Nearly 30,000 people are expected to show up for the afternoon Mass and a four-and-a-half-mile fence has been built on campus to beef up security. The pope will elevate Junipero Serra to sainthood, an 18th century Spanish missionary, the first ever canonization on U.S. soil.

The altar he'll speak from and the chair he'll sit on were custom designed by architecture students at Catholic University. They were chosen from an 18-team design competition.

The highly-anticipated Mass may serve as good practice for the pontiff's Sunday Mass in Philadelphia - which is expected to draw more than a million people.

But before that, the papal festivities Wednesday will go well into the evening, with a free concert at the Kennedy Center. The National Symphony Orchestra is expected to perform, but the pope himself is not on the bill.