Vatican foreign secretary Archbishop Paul Gallagher hailed the relationship between the United States and the Holy See as “strong and solid” on Wednesday during a visit to the nation’s capital.

The second highest-ranking Vatican diplomat’s remarks came during the opening of an exhibit at the U.S. Diplomacy Center marking the 35thanniversary of the formal establishment of diplomatic relations between the U.S. and the Vatican.

U.S. ambassador to the Vatican Callista Gingrich, who opened the ceremony, said the relationship was “one of the most consequential diplomatic partnerships in history.”

Gingrich described it as “a bond that existed since the founding of our nation,” that is today a “global partnership based on common values, mutual respect, and moral leadership.”

She outlined four major areas of shared commitment through “safeguarding human rights, defending religious freedom, mediating conflict, and providing humanitarian assistance,” around the globe.

The event and exhibit opening occurred alongside the Second Annual Ministerial to Advance Religious Freedom sponsored by the U.S. State Department, where on Wednesday Gingrich announced that in October the United States and the Vatican would co-sponsor a summit on religious freedom.

During his remarks, Gallagher chronicled the long history of U.S.-Holy See ties dating back two centuries before a formal agreement was established under Pope John Paul II and President Ronald Reagan in 1984.

Gallagher recalled that America’s first president, George Washington, assured Pope Pius VI freedom in his appointment of bishops marking the earliest engagement between the United States and the Holy See.

Long before formal ties were established, Gallagher noted that U.S. presidents enjoyed regular consultation and visits with Rome. Then in March of 1984 William Wilson was named as first ambassador to the Holy See.

On hand for the occasion were former U.S. ambassadors to the Vatican Jim Nicholson and Miguel Diaz, who served under Presidents George W. Bush and Barack Obama, respectively, current papal ambassador to the United States, Archbishop Christophe Pierre, and Ambassador for International Religious Freedom, former Senator Sam Brownback.

Nicholson also addressed the attendees, recalling that when Washington was approached about episcopal appointees to the United States he remarked that religious freedom was the reason the country was founded.

Should anyone doubt the effectiveness of the collaboration between the U.S. and the Vatican, Nicholson suggested that they look no further than the Soviet Union - a nod to the partnership between Reagan and John Paul II in bringing about the collapse of communism.

The Knights of Columbus, a principal partner of Crux, also sponsored the event.

Supreme Knight Carl Anderson also pointed to the collapse of the Soviet Union, which he told Cruxwas a collapse that was peaceful “without widespread violence,” and one of the major success stories for Vatican-U.S. diplomacy.

He also highlighted the “restoration or emergence of democracy in Latin America” where “military dictatorships were replaced by democracy” as part of the “strong leadership” of the two entities, along with the “attention to genocide in the Middle East and the rights of minorities in that region” as an area of ongoing partnership.

Anderson recalled that in 1982, Vatican Secretary of State Cardinal Agostino Casaroli traveled to the 100thanniversary convention of the Knights where he and President Ronald Reagan met in private to discuss the plans for the formal establishment of diplomatic ties between the U.S. and the Holy See.

“The United States at its best is also a moral leader,” said Anderson, and “the world needs both of these moral compasses.”

“The Holy See has a long diplomatic experience in virtually every country in the world. They bring a perspective that in many circumstances is unique,” he told Crux.

 The U.S. Diplomacy Center, which is the nation’s first museum dedicated to diplomacy, will feature the 35thanniversary exhibit marking diplomatic ties between the Vatican and the U.S. over the next year, and according to Gingrich, will host a series of ongoing discussions and events on the topic.

During his conclusion, Gallagher recalled Pope Francis’s visit to the United States in 2015 where he extolled the country’s commitment to religious liberty as a defining principle.

“We’re all called to be vigilant in preserving and defending that freedom,” said Gallagher.