Large events were held throughout the area, at locations including Soldier Field, Holy Name Cathedral, and the Saint Mary of the Lake Seminary.

Some sources claim that approximately 1 million people attended the closing day mass held at the seminary in nearby Mundelein, Illinois.

"Holy Father, permit the celebration of the next Eucharistic Congress to take place in Chicago and I promise you a million communions as a spiritual bouquet to your august presence."

[2] In 1924, Cardinal George Mundelein asked Pope Pius XI to declare Chicago the host city for the next International Eucharistic Congress.

The selection was also seen as a sign of the growing importance of Chicago, which, according to a 2019 article published by the University of Saint Mary of the Lake, was still considered "mission territory" until 1908.

[5] Mundelein also hoped that holding the congress in Chicago would demonstrate the strength of the Catholic Church in the city, where much of the political power was held by Protestant elites.

"[9] In March 1925, Bishop Thomas Louis Heylen, the president of the Pontifical Committee for International Eucharistic Congresses traveled to the city to scout locations for the event and discuss transportation issues with railroad and steamship companies.

[11] This sanctuary would hold an altar covered by a golden baldacchino, topped with a Christian cross and supported by four large columns.

[12] The north end of the altar consisted of a peristyle with alternating columns topped by either a cross or a bronze eagle, with laurel draped on the structure.

[10] American flags were flown prominently throughout the stadium,[13] which, according to historian Liam T. A. Ford, represented "Cardinal Mundelein's wish to emphasize the loyalty of U.S. Catholics to their country.

"[14] In February, the congress was discussed in a bulletin published by the National Catholic Welfare Conference, with dates for the event set for June 20–24 of that year.

[3][4] In April, members of the German delegation had already arrived in the city and began actively planning their events for the congress.

[16] Various civic groups in the city, including the Chicago Association of Commerce, organized several dozen committees to prepare for the event, while transportation companies also made arrangements.

[18] As part of the congress, over 3,000 priests were called to attend to confessions, and religious sisters were requested to make over 4.5 million hosts to be used during masses.

[19] On June 6, a group consisting of 6 cardinals and 60 bishops, serving as the Pope's delegation to the congress, embarked from France to the United States aboard the RMS Aquitania.

[26] On June 18, the papal delegation was formally welcomed at the Chicago Coliseum in an event attended by numerous elected officials and prominent citizens.

Illinois Governor Len Small was also present, while business magnate Samuel Insull greeted the delegation on behalf of Protestants and non-Catholics.

[3] The congress officially began that day with a large procession that included representatives from all attending religious orders, 750 students from Quigley Preparatory Seminary, 500 monsignors, 300 bishops, 60 archbishops, and 10 cardinals.

[26] Seminarians from Saint Mary of the Lake, accompanied by members of the Order of St. Gregory the Great and the Knights of Malta, led the procession for the mass.

[5] On June 23, deemed Higher Education Day, a mass written by Johann Baptist Singenberger was performed by 3,000 high school and college students.

[33] The 96-minute movie, heralded by Doherty as "the first premapped feature-length record of an unfolding historical event", premiered at Al Jolson's Theater in New York City on November 8 before a sell-out crowd.

[34][2] A 1926 article published in The New York Times states that up to 1 million people were expected to attend the closing ceremony at Saint Mary of the Lake Seminary.

[9] According to contemporary records from the Chicago New World, approximately 8.3 million people participated in the congress from the arrival of the papal delegation on June 17.

[2] Following the congress, the Benedictine Sisters of Perpetual Adoration were invited to build a chapel near the Saint Mary of the Lake campus in Libertyville, Illinois.