The bell tower of St. Paul's was completed in the summer of 1876. The construction costs, in the region of $17,000, were taken on by one person, Miss Catharine Lorillard Wolfe of New York. In this way, although funds were lacking in other areas of the constructions, the work on the tower was able to continue uninterrupted, so that by the beginning of July 1876 the cross had been placed on top.

The tower was built to house a chime of 23 bells, the gift of Thomas Messenger of Brooklyn, which were cast by the Belgian foundry of Severin Van Aerschodt, Louvain. The bells were received in Rome in June 1876, and three of them were in place in time to sound for the first time on 3rd June, the anniversary of the foundation of the constitutional government in Italy. The dedication ceremony was held on the anniversary of American Independence, 4th July, 1876.

The largest of the bells, which weighs three quarters of a ton, bears the tribute to St. Paul, Rome's greatest martyr, in the words 'Verbum Dei Non Est Alligatum' (the Word of God is not bound), and below: To the glory of God and in Honor of His Holy Apostle Paul, January 29, year of our Lord 1876 and in honour of the Independence of the United States of America 100.

The other bells are inscribed with phrases from the Lord's Prayer, the Apostle's Creed and the Gloria. What follows is a listing of the bells as appears in the foundry books, giving the tone, wieght and diameter. We are grateful to Mr. Paul-Felix Vernimmen, great-grandson of the maker, for providing this information:

"As this is still the only carillon in Italy it arouses great interest here. Some years ago when the royal family were still living in the Quirinal the children were wont to go into the garden to listen to the bells of a Sunday morning, and when they heard a tune that had been taught them by their Waldensian nurses they sang the hymn… in French. I once had a request that we would play the favorite hymn of the little Prince: it was Mr. Sankey's 'Pull for the shore, sailor, pull for the shore'".
(W. Lowrie, Fifty Years of S. Paul's American Church, Rome - Rome 1926)

"St. Paul's is much admired for its beautiful mosaics by Burne-Jones, and its peal of bells, 23 in number which play sacred airs like the churches in Belgium…"
(A. D. Tani, 'A New Guide to Rome' - Rome, 1925)