The Swiss Civil War (Sonderbund War)

November 29, 1847:

 The Sonderbund is defeated by the joint forces of other Swiss cantons under General Guillaume-Henri Dufour. The Sonderbund War (German: Sonderbundskrieg) of November 1847 was a civil war in Switzerland. It ensued after seven Catholic cantons formed the Sonderbund ("separate alliance", in German) in 1845 in order to protect their interests against a centralization of power. The end of the war was the end of what is now known as the period of Restoration and Regeneration; it led to the rise of Switzerland as a federal state.
The Sonderbund consisted of the cantons of Lucerne, Fribourg, Valais, Uri, Schwyz, Unterwalden and Zug, all predominantly Catholic but then ruled by Conservative administrations. The cantons of Ticino and Solothurn, predominantly Catholic but then ruled by liberal administrations, did not join the alliance.
General Guillaume-Henri Dufour led the federal army of 100,000 and defeated the Sonderbund under Johann-Ulrich von Salis-Soglio in a campaign that lasted only from November 3 to November 29, and claimed fewer than a hundred victims. He ordered his troops to care for the injured, anticipating the formation of the Red Cross in which he participated a few years later. Major actions were fought at Fribourg, Geltwil, Lunnern, Lucerne, and finally at Gisikon, Meierskappel, and Schüpfheim, after which Lucerne capitulated on 24 November.

In 1848, a new Swiss Federal Constitution ended the almost-complete independence of the cantons and transformed Switzerland into a federal state. The Jesuits were banished from Switzerland. This ban was lifted on 20 May 1973, when 54.9% of the population and 16.5 cantons out of 22 accepted a referendum modifying the Constitution.

Switzerland is my favorite answer to the right-wing email claim that no nation has ever survived as a bilingual or multilingual nation:

Switzerland comprises three main linguistic and cultural regions: German, French, and Italian, to which the Romansh-speaking valleys are added. The Swiss therefore do not form a nation in the sense of a common ethnic or linguistic identity. The strong sense of belonging to the country is founded on the common historical background, shared values (federalism, direct democracy, neutrality) and Alpine symbolism. The establishment of the Swiss Confederation is traditionally dated to 1 August 1291; Swiss National Day is celebrated on the anniversary.

Not only are there 3 main languages and one minor language, but the nation was at the heart of the Reformation, and the population is split by religion.  In spite of that, the nation persists.  I guess we have a chance with our little experiment here in the New World.

I also find it funny that the Jesuits got kicked out of Switzerland from 1848 to 1973.  They have a pretty lengthy history of not being able to play well with others, and being asked to leave by various potentates, although they were sometimes used as scapegoats.  Heck, even the Pope (under secular pressure) shut them down in most of Europe in 1773.