What event brought seven Catholic cantons of Switzerland together to create a federal constitution?
Switzerland as a federal state: The rise of Switzerland as a federal state began on 12 September 1848, with the creation of a federal constitution in response to a 27-day civil war in Switzerland, the "Sonderbundskrieg". Sonderbund War:  It ensued after seven Catholic cantons formed the "Sonderbund" ("separate alliance") in 1845 to protect their interests against a centralization of power.
i don't know