The Diocese of Kansas City-Saint Joseph encompasses the following counties: Andrew, Atchison, Bates, Buchanan, Caldwell, Carroll, Cass, Clay, Clinton, Daviess, DeKalb, Gentry, Grundy, Harrison, Henry, Holt, Jackson, Johnson, Lafayette, Livingston, Mercer, Nodaway, Platte, Ray, St. Clair, Vernon and Worth.

In present-day Hannibal, Missouri, the first Catholic masses were celebrated by the Belgian missionary, Reverend Louis Hennepin, in 1680 at Bay de Charles.

In 1826, Pope Leo XII erected the Diocese of St. Louis, covering the new state of Missouri along with vast areas of the American Great Plains.

[7] On September 10, 1880, Pope Leo XIII established the Diocese of Kansas City, with territories taken from the Archdiocese of St.

[11] In 1933, Lillis drafted a resolution signed by many of his fellow Catholic bishops and 350 priests in an effort to end lynchings of African-Americans.

[15] In July 1956, Pius XII redrew the diocesan boundaries in parts of Missouri: After O'Hara died in September 1956, Cody automatically succeeded him as bishop.

He objected specifically to NCR's stands on artificial birth control and priestly celibacy, along with its criticism of the church hierarchy.

[20] Pope John Paul II then named Bishop Raymond Boland of the Diocese of Birmingham to replace Sullivan.

[21] In 2004, Reverend Robert Finn of St. Louis was named by John Paul II as coadjutor bishop of the diocese.

In September 2014, Pope Francis ordered an investigation into Finn's tenure as bishop, to be conducted by Canadian Archbishop Terrence Prendergast.

As part of the settlement, Bishop Finn agreed to report any future suspected abuse to law enforcement.

In December 2010, a technician discovered inappropriate images of children on Ratigan's computer and notified diocesan officials.

[30][31] In June 2011, Finn appointed former U.S. Attorney Todd P. Graves to investigate diocesan policies and procedures on sexual misconduct by clergy.

[33] In October 2011, a grand jury indicted both the diocese and Finn for failing to report suspected child abuse, a criminal misdemeanor.

[29] In August 2019, Reverend Benedict Neenan, abbot of Conception Abbey, released a list of eight monks who were credibly accused of committing acts of sex abuse while serving in the diocese.

[38] Neenan also issued an "unconditional apology to all victims and their families affected by the evil of clergy sexual abuse.

[39] Reports surfaced that during the 1970s, Monsignor Thomas O’Brien and Hart allegedly used a house owned by O'Brien on Lake Viking in Missouri to sexually abuse children.

Later that month, Wyoming Attorney General Bridget Hill announced that her office would not pursue criminal charges against Hart.

[42] In July 2020, two new lawsuits were filed in Jackson County Circuit Court against the diocese, involving alleged rape by two priests in 2018.

In the letter, Johnston asked voters to examine which party supported so-called moral issues such as abortion rights.