Reading The Song of Bernadette, I'm finding that a refresher course in mid-nineteenth-century France is helpful, although the story can stand alone. For events prior to 1830, see the timeline I did for The Red and the Black.
1830 Beginning of the July Monarchy with the "Three Glorious Days" leading to the abdication of Charles X (Bourbon dynasty) and his replacement by Louis-Philippe (Orleans dynasty). France becomes a constitutional monarchy dominated by the haute bourgeoisie. The July Monarchy will be marked by multiple popular uprisings and attempted revolutions.
Catherine Labouré begins having the Miraculous Medal visions.
5-6 June 1832 The June Rebellion, an unsuccessful uprising against the July Monarchy. This is the uprising in Hugo's Les Miserables.
7 January 1844 Marie-Bernadette Soubirous is born.
June 1846 Pope Gregory XVI dies. Due to Italian unrest, many foreign Cardinals do not attend, skewing the conclave very Italian. The Italians are largely split between liberal and conservative factions; by joining with people not definitely in either camp, the liberals manage to elect a man with a widespread reputation as a liberal bishop. Thus Giovanni Maria Mastai-Ferretti becomes Pope Pius IX.
19 September 1846 Marian apparitions at La Salette, France.
22 February 1848 The February Revolution. Louis-Philippe abdicates and the July Monarchy gives way to the Second French Republic. Similar revolutions will start spreading through a number of countries in Europe and South America; Pius IX is forced to flee Rome due to uprisings in Italy under Garibaldi.
10 December 1848 Louis Napoleon Bonaparte is elected President of the French Republic.
1849 French armies restore the Pope to Rome.
1851 Since he cannot be re-elected Louis Napoleon Bonaparte suspends the Assembly and elects himself President for Life.
1852 The Second French Republic becomes the Second French Empire as Louis Napoleon Bonaparte makes himself Emperor Napoleon III. The take-over is confirmed by referendum. The Bonapartist party controls the French parliament by an overwhelming majority.
8 December 1854 Pope Pius IX issues the bull Ineffabilis Deus defining the dogma of the Immaculate Conception of Mary.
11 February to 16 July 1858 Bernadette Soubirous sees the Virgin Mary at Lourdes. According to Bernadette, in the sixteenth and last vision the Virgin Mary says, "I am the Immaculate Conception."
7 November 1858 Official ecclesial investigation of the Lourdes apparition begins.
1859 The Franco-Austrian War, also known as the Second Italian War of Independence; as a result, France will gain the territories of Savoy and Nice and the Papal States will lose the northern Papal Legations.
Death of Jean-Baptiste-Marie Vianney, the Curé d'Ars.
1860 Lourdes investigation ends with approval.
The Druze-Maronite Massacre begins in Syria, leading France to intervene; one result of this will be the establishment of the independent Mount Lebanon Mutassifariate in 1861, which will last until World War I.
1861 President Benito Juarez of Mexico refuses to pay interest on loans to Mexico; France in retaliation invades Mexico, overthrowing its republican government and placing Maximilian I at the head of the Second Mexican Empire, which is basically serves as a puppet state of France and a French ally in North America.
Victor Emmanuel II is proclaimed King of Italy and Rome the Italian capital, despite the fact that Rome is in (what little is left of) the Papal States, and not in the Kingdom of Italy.
Abbé Dominique Peyramale and Monsignor Bertrand-Sévère Mascarou Laurence oversee the acquisition of the Lourdes grotto and area around it.
1864 Victor Emmanuel II negotiates the removal of French troops from Rome.
1865 No longer engaged in a civil war, the United States begins actively supporting Juarez and his loyalists in Mexico; Napoleon III, unwilling to get into a war with the United States, begins withdrawing French troops.
1866 The last French troops leave Rome, against the urging of the Pope for them to stay.
1867 The Republic of Mexico is restored and Maximilian I is executed.
The Luxembourg Crisis threatens to plunge Europe into a massive war. France attempts to buy Luxembourg from the Netherlands. King William III accepts, but technically Luxembourg was also a member of the German Confederation, and the deal required Prussian permission. The French had assumed that this was already promised them by Otto von Bismarck in exchange for France's neutrality in the Second Schleswig War, but no official treaty was made, and Bismarck reneges on the deal. Napoleon III offers to settle for the removal of German troops from Luxembourg City. The other Great Powers of Europe, fearing that a Franco-Prussian war will suck them in, push heavily for an international conference, leading to the London Conference and Luxembourg's neutrality.
1869 Bonapartists are dealt a terrible blow in parliamentary elections as they barely manage to uphold their majority against the liberal opposition, due to increasing unrest among the working class, despite the fact that their campaign expenses are paid by the government and their districts often gerrymandered in their favor. The "White Overalls" riots take place shortly afterward.
Pius IX convenes the First Vatican Council.
1870 A referendum confirms popular support for liberal reforms. The Franco-Prussian War begins. Napoleon III is captured at the Battle of Sedan and the Second French Empire collapses. The Government of National Defense, usually regarded as the first government of the Third Republic, is created as a provisional government. The Germans invade Alsace and Lorraine.
Unprotected by France, Rome falls to the Italian army; Pius IX becomes "the Prisoner of the Vatican" and the Vatican period of the papacy begins.
1871 Thoroughly defeated by Prussia, France capitulates and faces severe war reparations. National elections are held; the resulting National Assembly passes unpopular financial laws to handle the war reparations, leading to extensive unrest. The socialist Paris Commune rises up in revolt and takes over Paris; their program includes the first clear affirmation of laïcité. The government manages to retake Paris, at considerable cost of lives.
Karl Marx publishes the pamphlet, The Civil War in France, praising the Communard attempt and holding it up as the harbinger of a new society; but the Communard attempt also will mark a turning point in Marx's thought, as he draws the conclusion that it is not effective for the working class to rise up and attempt to directly wield the instruments of state, which will lead to the split between Communists and anarchists in the International Workingmen's Association.
Marian apparitions at Pontmain, which will be later approved.
1875 The French Constitutional Laws of 1875 stabilize the form of the Third Republic.
1876 Catherine Labouré dies.
The Basilica of the Immaculate Conception is consecrated at Lourdes.
February 1878 Pope Pius IX dies. Vincenzo Gioacchino Raffaele Luigi Pecci becomes Pope Leo XIII. One of the many works of his papacy will be an ongoing attempt to overcome the gap between the papacy and the French Republic.
16 April 1879 Marie-Bernadette Soubirous dies.
21 August 1879 Marian apparitions at Knock, Ireland, which will later be approved.
1881-1882 Jules Ferry begins to re-introduce the idea of laïcité into French government.