They have also spoken up for the faith in public life. In the early 1900s the order protested anti-Catholic policies in Cuba and the Philippines after the Spanish-American War. Knights objected to a strict French secularism law passed in 1905.
In the 1920s the Knights of Columbus opposed the persecution of the Church in Mexico, where anti-clerical Mexican leaders had made strict laws to hamper the clergy. Priests who were not discreet risked execution. The Knights had "a real impact" on the thinking of the U.S. government, the American people and global opinion, Walther said.
"The Knights of Columbus was an organization decades ahead of its time on the integration issue," Walther noted. The organization had African-American members in the 19th century and was the only U.S. group to run racially integrated recreation and hospitality centers for soldiers in World War I.
Responding to the exclusion of African-Americans from American history, the Knights commissioned the African-American scholar and civil rights advocate W.E.B. DuBois to write the book "The Gift of Black Folk."
"We wanted to make sure the contributions of African-Americans were not neglected in the story of the country," Walther said. The order also commissioned books about Jewish and Hispanic Americans.
"You see the Knights of Columbus having a real impact that was transformative in a lot of ways, and groundbreaking in others," he added.
In the 1920s, the rise of the Ku Klux Klan empowered its strongly anti-Catholic politics. The Knights worked "to stop the Klan from outlawing Catholic education in Oregon" and funded the court case that led to a Supreme Court victory against a state law that mandated that all children attend public schools.
In the 1930s and 1940s, the organization spoke out against Nazi attacks on Jews and Catholics. Before and during the Cold War, it objected to communist persecutions. The knights backed religious freedom efforts in Poland and gave assistance to Pope John Paul II's work to promote human rights in communist eastern Europe.
More recently, the Knights have supported persecuted Christians and other religious minorities in the Middle East, especially those threatened by the Islamic State group. The order was instrumental in an official U.S. declaration recognizing the persecution as genocide.
In researching the book, Walther said the co-authors rediscovered some prominent people in history whose membership in the Knights of Columbus had been forgotten. This included Jim Thorpe, the athlete and Olympic gold medalist of the early 20th century; John Myon Chang, one of the founding fathers of the modern state of South Korea; and Prime Minister of Canada Louis St. Laurent.
"These men were leading figures and joined the Knights out of their sense of the faith and also because the knights were a really important element in their country and in their communities," Walther said.
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Other prominent men who were well-known Knights of Columbus include Major League Baseball Hall of Fame inductee Babe Ruth, U.S. President John F. Kennedy, National Football League champion coach Vince Lombardi, and poet and World War I soldier Joyce Kilmer.
Charitable figures of the Knights of Columbus are tallied together, representing thousands of local councils and 2 million men who "contribute in an incredible way at this local level that then generates this global impact.
Walther described local councils as "the backbone of the Knights of Columbus." When Knights pioneered the first national blood drive, this was driven by action in the local councils.
Walther had praise for his co-author and wife Maureen, whose connections to New Haven meant the early history of the Knights was deeply interesting to her as a local.
"She's just an amazing researcher," he added. "She found incredible nuggets on so many different elements. She uncovered a lot of things that might otherwise have been missed in the annals of Knights of Columbus."
"The Knights of Columbus: An Illustrated History" will be released on March 9, and is now available for preorder.