A look at the sites Pope Francis will visit while in the United States:
ANDREWS AIR FORCE BASE
Pope Francis will arrive in the United States on Tuesday afternoon through Andrews Air Force Base.
President Barack Obama and first lady Michelle Obama will travel to the base in Maryland, just outside Washington, to greet the pope. The base is home to Air Force One and the president travels there regularly for his out-of-town trips, but he hardly ever goes there to welcome a visiting dignitary.
One exception came last year when Obama met French President Francois Hollande at Andrews. When Pope Benedict XVI visited in 2008, then-President George W. Bush and his wife, Laura, greeted him at Andrews.
THE WHITE HOUSE
Pope Francis will visit the White House on Wednesday morning, becoming only the third pope to visit the home. The others were Pope Benedict XVI in 2008 and Pope John Paul II, who visited President Jimmy Carter in 1979.
Francis will be greeted as most heads of state are, with his car pulling slowly up the South Lawn's driveway to the spot where a red carpet will be rolled out and the Obamas will be waiting.
Thousands of invited guests, including many Catholics, will gather on the lawn to receive Francis.
Shortly after he arrives on the South Lawn, the anthems of the U.S. and the Vatican will play, following military honors that include a 21-gun salute and band members dressed in colonial garb. Obama will welcome the pope with remarks followed by a reciprocal address from Francis. They will then head inside the White House and reappear on the balcony.
Inside, Francis will sign the official guest book. He and Obama will exchange gifts before meeting in the Oval Office.
Following the visit, the Pope will travel in the Popemobile along streets near the White House.
CATHEDRAL OF ST. MATTHEW THE APOSTLE
The domed cathedral where Pope Francis will meet with all the U.S. bishops is best known as the site where Washington mourned the death of the first Catholic president, John F. Kennedy. He is memorialized with a marble plaque in the cathedral floor at the site of the 35th president's funeral.
The parish dates back to 1840 as the fourth Catholic church established in the District of Columbia.
St. Matthew's is the mother church or seat of the Archdiocese of Washington, and the current church hosted its first Mass in 1895. It was designated a cathedral in 1939 when the combined Archdiocese of Baltimore and Washington was created. The two regions were later separated. The cathedral was placed on the National Register of Historic Places in 1974.
Inside the cathedral, Pope Francis and the bishops will say the midday prayer.
BASILICA OF THE NATIONAL SHRINE OF THE IMMACULATE CONCEPTION
Next to Catholic University stands the largest Catholic church in the United States and North America, the Basilica of the National Shrine of the Immaculate Conception. The basilica is located in Washington's Brookland neighborhood, which is nicknamed "Little Rome" for its numerous seminaries, monasteries, convents and other Catholic sites.
Ground was broken for the church in 1920, and the shrine was dedicated in 1959. The massive basilica now stands as one of the 10 largest churches in the world. It was designed in a Romanesque-Byzantine style with a colorful dome, but church officials say it was not designed to imitate or duplicate any other church in the world.
Pope John Paul II became the first reigning pope to visit the church in 1979 and elevated it to the status of minor basilica in 1990. Pope Benedict XVI visited in 2008 to worship and meet with the U.S. bishops. A church spokeswoman says about 1 million people visit the basilica each year.
Pope Francis will celebrate Mass with a crowd of about 30,000 from the basilica's east portico, facing the campus of Catholic University.
The Mass will serve as a canonization for Franciscan missionary Junipero Serra to make him a saint. The elevation of the California missionary will give the U.S. its first Hispanic saint. Serra died in 1784.
CATHOLIC UNIVERSITY OF AMERICA
Catholic University, the national university of the Catholic Church in the U.S., was founded in 1887 and is run by the U.S. bishops. The university mall will host a crowd of Hispanic Catholics and Washington-area parishioners to celebrate Mass with Pope Francis.
Catholic University enrolls about 6,800 students from all 50 states and about 86 countries.
THE U.S. CAPITOL
On Thursday morning, Pope Francis will visit the U.S. Capitol to give an address to a joint session of Congress, the first time a pope will address the body of 434 House members and 100 senators. Also expected to attend: members of the Supreme Court and the Cabinet. The House chamber where Francis will address members of Congress is where the president gives his yearly State of the Union speech.
Three foreign heads have addressed a joint meeting of Congress this year: Israeli Prime Minister Benjamin Netanyahu, Afghan President Ashraf Ghani and Japanese Prime Minister Shinzo Abe.
Large video screens are being set up on the West Front of the Capitol facing the National Mall so thousands can watch Francis' speech from outside. Each lawmaker also can request 50 standing-room-only tickets for the West Lawn, plus one ticket for guests who can sit in the cavernous Cannon Caucus Room and watch the pontiff on video.
After the address, the pope is expected to appear on the Capitol balcony. The scene is a little less than picture-perfect: The Capitol's dome is currently shrouded in scaffolding as part of a multi-year restoration project.
After addressing Congress, Pope Francis will visit Catholic Charities. Officials with the charity say it is the largest provider of social services in the region, serving about 115,000 people per year.
Pope Francis will make a brief visit to St. Patrick's Church, the oldest Catholic Church in the nation's capital. Then he will visit the headquarters for Catholic Charities next door. The charity serves dinner to about 300 homeless people daily at the site, and it will serve a meal during the pope's visit.
The visit is his last stop in Washington before he heads to New York.
ST. PATRICK'S CATHEDRAL
After arriving at John F. Kennedy International Airport on Thursday evening, Pope Francis will be taken to St. Patrick's Cathedral in Manhattan for evening prayers.
The timing is fortuitous: A three-year restoration project at the Fifth Avenue edifice has just wrapped up. The $175 million renovation was thorough -- the entire exterior was washed, all the way to the top of the 330-foot spires. Every glass panel in all 75 stained glass windows was cleaned, and the massive bronze doors at the entrance were restored.
St. Patrick's is the seat for the Roman Catholic Archdiocese of New York. The first Mass was celebrated there in 1879. It was declared a national landmark in 1976. It gets about 5 million visitors a year.
On Friday morning, Pope Francis will address diplomats and world leaders just before the opening of the summit at the United Nations General Assembly that will focus on goals in combatting poverty and protecting the environment. The pope will be speaking in the general assembly hall at the U.N.'s headquarters on Manhattan's east side.
NATIONAL SEPTEMBER 11 MEMORIAL & MUSEUM
The museum and memorial commemorating those lost in the Sept. 11 attacks in lower Manhattan and the events of the day will be the site of a multi-faith service, which the pope will participate in. The museum pavilion is situated between the two reflecting pools that mark the footprints of where the twin towers used to stand.
OUR LADY QUEEN OF ANGELS SCHOOL
Our Lady Queen of Angels, on 112th Street in East Harlem, is a Catholic school with approximately 290 children from pre-k to eighth grade. Six students from third and fourth grades will meet Pope Francis, along with other children from the city's Catholic schools. Our Lady Queen of Angels parish around the corner closed in 2007 as part of the broad reorganization of the Archdiocese of New York.
No visit to New York City could be considered complete without a jaunt through Central Park, not even for the pope. He's due to take a processional through part of the green space designed by Frederick Law Olmsted and Calvert Vaux. The pope's route will take him along the park's West Drive, from 72nd to 60th streets.
This is the chance for some members of the public to catch a glimpse of the pontiff. City officials said more than 93,000 people entered a lottery for free pairs of tickets to the processional, and about 80,000 tickets were given out. Those going to the event will have to go through airport-style security checkpoints, and are banned from carrying items like backpacks.
MADISON SQUARE GARDEN
The pope's final event in New York City will be a Mass on Friday evening at Madison Square Garden, more commonly home to sporting events and concerts. The arena can hold around 18,000 people. It's located on top of Pennsylvania Station, a major transportation hub, in midtown Manhattan.
Tickets for the Mass were distributed through the archdiocese's parishes.
The pope leaves for Philadelphia on Saturday morning.
CATHEDRAL BASILICA OF STS. PETER AND PAUL
The Cathedral Basilica of Sts. Peter and Paul, the mother church of the Archdiocese of Philadelphia, occupies a prominent spot, its green dome and Corinthian columns rising between City Hall and the art museum steps made famous by "Rocky."
The 150-year-old cathedral is hosting the first event of Francis' two-day visit to the city: a Mass for about 1,600 local parishioners and clergy on Saturday, about an hour after he arrives from New York City.
Pope John Paul II spoke at the cathedral in 1979, the only other papal visit to Philadelphia. He heralded the city as a symbol of freedom and fraternity and said he was praying for residents to ensure no one there felt disrespected, abandoned, rejected or alone.
The start of construction on the cathedral in 1846 didn't evoke as much harmony. The project rekindled tensions after Protestant riots two years earlier that targeted Irish Catholics. To prevent vandalism, architect Napoleon LeBrun designed the cathedral without street-level windows.
Independence Hall is the birthplace of American democracy, the building where the founding fathers debated and ratified the Declaration of Independence and signed the U.S. Constitution.
The red-brick structure, immortalized on the back of the $100 bill, will provide the backdrop for Pope Francis' speech Saturday on immigration and religious freedom.
Independence Hall, which opened in 1753 as Pennsylvania's colonial legislature, is located across a cobblestone street from where the Liberty Bell now resides.
About 40,000 people are expected to pack the lawn for Francis' speech, but the disruption to historic sites will only last a day. Independence Hall and the Liberty Bell will close Saturday but will be open Friday and Sunday on a first come, first served basis.
BENJAMIN FRANKLIN PARKWAY
The Ben Franklin Parkway is a mile-long boulevard stretching from Philadelphia's City Hall to the Philadelphia Museum of Art. It's the city's cultural center and the epicenter of papal activities.
Organizers expect a half-million people for the Festival of Families concert celebration on Saturday and more than a million people for Francis' Mass the next day. He'll parade down the parkway's outer lanes before both events to give pilgrims an up-close view.
Donna Crilley Farrell, executive director of the triennial World Meeting of Families event that's attracting Francis to the U.S., called the parkway the best place in the country to see the pope.
Papal events will also be broadcast on 40 huge screens throughout the city for crowds not close to the stage or altar, which is being built near the museum.
The parkway, modeled on the Champs-?lysΘes in Paris, was built between 1917 and 1926 in an early attempt at urban renewal. The area had been a neighborhood.
It's lined with trees, statues, sculptures and cultural institutions, including the Franklin Institute science museum and the Barnes Foundation art museum.
CURRAN-FROMHOLD CORRECTIONAL FACILITY
The largest jail in Philadelphia, the Curran-Fromhold jail houses more than 2,800 male inmates. Most of them are either awaiting trial or serving sentences of up to two years.
Francis is scheduled to meet with about 100 inmates and some of their families on Sunday -- fulfilling a goal of his trip to visit with people incarcerated in the U.S.
Monsignor William Lynn, jailed for his handling of priest sexual-abuse complaints, had been housed at Curran-Fromhold, but he was moved to a state prison near Scranton shortly after the pope's itinerary was announced.
Curran-Fromhold is named for the only two Philadelphia prison workers killed in the line of duty: Warden Patrick Curran and Deputy Warden Robert Fromhold, who were attacked by inmates at Holmesburg Prison on May 31, 1973.
ST. CHARLES BORROMEO SEMINARY
Located on a pastoral 75 acres just outside Philadelphia, St. Charles Borromeo Seminary prepares men for the priesthood and the diaconate and provides high-level religious instruction for lay men and women.
Bishop Francis Kenrick founded St. Charles Borromeo, named for the reforming 16th century cardinal, in his downtown Philadelphia home in 1832. It moved four times, including briefly to where the Cathedral Basilica of Saints Peter and Paul now stands, before landing in suburban Wynnewood in 1871.
Pope Francis is expected to stay at St. Charles while in Philadelphia and will greet bishops from around the world there on Sunday. Francis will also pose for a photograph with seminarians, recreating an image featuring Pope John Paul II in 1979.
The seminary has also welcomed Mother Teresa and three cardinals who later became pope, including Cardinal Joseph Ratzinger, who became Pope Benedict XVI.
Associated Press reporters Jessica Gresko and Brett Zongker contributed to this report from Washington, Deepti Hajela contributed from New York and Michael Sisak from Philadelphia.