My parents, who were semi-practicing Presbyterians, couldn't explain to me what the title "Saint" meant, other than to say it was a great honor of some kind. They did not, to their credit, use it as an occasion to bash the Catholic Church. Upon my conversion and entry into the Church in 2005, after I started paying attention to the solemnities, feasts and memorials of the liturgical calendar, I was pleased to learn more about the man for whom the city of my birth was named. Here are the last few paragraphs from the Catholic Encyclopedia's quite lengthy entry about St. Louis:
"St. Louis led an exemplary life, bearing constantly in mind his mother's words: "I would rather see you dead at my feet than guilty of a mortal sin." His biographers have told us of the long hours he spent in prayer, fasting, and penance, without the knowledge of his subjects. The French king was a great lover of justice. French fancy still pictures him delivering judgements under the oak of Vincennes. It was during his reign that the "court of the king" (curia regis) was organized into a regular court of justice, having competent experts, and judicial commissions acting at regular periods. These commissions were called parlements and the history of the "Dit d'Amiens" proves that entire Christendom willingly looked upon him as an international judiciary. It is an error, however, to represent him as a great legislator; the document known as "Etablissements de St. Louis" was not a code drawn up by order of the king, but merely a collection of customs, written out before 1273 by a jurist who set forth in this book the customs of Orléans, Anjou, and Maine, to which he added a few ordinances of St. Louis.
St. Louis was a patron of architecture. The Sainte Chappelle, an architectural gem, was constructed in his reign, and it was under his patronage that Robert of Sorbonne founded the "Collège de la Sorbonne," which became the seat of the theological faculty of Paris.
He was renowned for his charity. The peace and blessings of the realm come to us through the poor he would say. Beggars were fed from his table, he ate their leavings, washed their feet, ministered to the wants of the lepers, and daily fed over one hundred poor. He founded many hospitals and houses: the House of the Felles-Dieu for reformed prostitutes; the Quinze-Vingt for 300 blind men (1254), hospitals at Pontoise, Vernon, Compiégne.
The Enseignements (written instructions) which he left to his son Philip and to his daughter Isabel, the discourses preserved by the witnesses at judicial investigations preparatory to his canonization and Joinville's anecdotes show St. Louis to have been a man of sound common sense, possessing indefatigable energy, graciously kind and of playful humour, and constantly guarding against the temptation to be imperious. The caricature made of him by the envoy of the Count of Gueldre: "worthless devotee, hypocritical king" was very far from the truth. On the contrary, St. Louis, through his personal qualities as well as his saintliness, increased for many centuries the prestige of the French monarchy (see FRANCE). St. Louis's canonization was proclaimed at Orvieto in 1297, by Boniface VIII. Of the inquiries in view of canonization, carried on from 1273 till 1297, we have only fragmentary reports published by Delaborde ("Mémoires de la société de l'histoire de Paris et de l'Ilea de France," XXIII, 1896) and a series of extracts compiled by Guillaume de St. Pathus, Queen Marguerite's confessor, under the title of "Vie Monseigneur Saint Loys" (Paris, 1899)."
You can read the whole thing here.
Laudator Jesus Christus!