Pope US visit
Pope Francis speaks during a multi-religious prayer for peace at the 9/11 Memorial and Museum on September 25, 2015 in New York City. Pope Francis is in New York on a two day visit and will carry out a number of engagements including a Papal motorcade through Central Park and a Mass in Madison Square Garden. REUTERS/Justin Sullivan/Pool

NEW YORK (Reuters) - Pope Francis, a day after addressing the United Nations in New York, travels on Saturday to Philadelphia, the birthplace of American independence, to promote the issue of religious freedom on the penultimate day of his first visit to the United States.

The 78-year-old Argentine pontiff, due to fly from New York and arrive in Philadelphia around 9:30 a.m. EDT, is set to go to the site of Independence Hall, the 18th century red-brick building where the nation's two bedrock documents, the Declaration of Independence and Constitution, were adopted.

Francis will hold a rally there with Hispanic and other immigrants on the theme of religious freedom. The event combines two issues about which Francis is most concerned: the plight of immigrants seeking a better life for themselves and their families, and the freedom to practice religion.

The pope has denounced the persecution of Christians and other religious minorities in the Middle East.

In his address at the U.N. General Assembly on Friday, the pope noted that Christians and others in the Middle East "have been forced to witness the destruction of their places of worship, their cultural and religious heritage, their houses and property" and have been forced either to flee or face death or enslavement.

In his address, the pope also denounced "a selfish and boundless thirst for power and material prosperity" in the world that causes the misuse of natural resources and the exclusion of "the weak and disadvantaged."

The leader of the world's 1.2 billion Roman Catholics also is set to celebrate a morning Mass in Philadelphia's Cathedral Basilica of Saints Peter and Paul and lead an evening prayer service at the World Meeting of Families, a congress to promote family values.

The pope wraps up his six-day U.S. trip on Sunday with a Mass outside the neoclassical Philadelphia Art Museum expected to attract about 1.5 million people.

In New York on Friday, the pope prayed at the memorial to those killed in the Sept. 11, 2001, attacks, was greeted by about 80,000 people as he drove through sprawling Central Park and celebrated Mass at the famed Madison Square Garden sports arena before about 20,000 people.

Near Independence Hall, where the 13 American colonies declared independence from Britain in 1776, Francis will speak from a lectern used by President Abraham Lincoln for his Gettysburg Address, declaring that "government of the people, by the people, for the people, shall not perish from the Earth."

Lincoln's 272-word address, given on Nov. 19, 1863 after the bloodiest battle of the U.S. Civil War, is famed as a celebration of U.S. values and a defense of the conflict that ended slavery in the nation.

Downtown Philadelphia will be on lockdown during the papal visit, with concrete barricades and miles of 8-foot (2.4-meter) tall metal fences encircling the area, limiting pedestrians and vehicle traffic to large swaths of the city.

Vatican spokesman Father Federico Lombardi acknowledged to reporters on Friday night that the pope was tired amid a packed schedule on the trip. He said the pope usually has physical therapy for a leg problem but cannot undergo therapy during trips so was having some difficulty with steps.

(Additional reporting by Ian Simpson, Scott Malone and Laila Kearney; Writing by Will Dunham; Editing by Lisa Shumaker)