The territorial evolution of Switzerland occurred primarily with the acquisition of territory by the historical cantons of the Old Swiss Confederacy and its close associates. This gradual expansion took place in two phases, the growth from the medieval Founding Cantons to the "Eight Cantons" during 1332–1353, and the expansion to the "Thirteen Cantons" of the Reformation period during 1481–1513. The Helvetic Republic (formed 1798) as revised in the Act of Mediation (1803) added further territories of former Associates of the Swiss Confederacy, notably those of the Abbey of St. Gall and the Three Leagues. The territories of the Valais, the Swiss Jura and Geneva were added to the "restored" Confederacy following the Congress of Vienna in 1815. The restored Confederacy remained a union of nominally independent states until the formation of Switzerland as a federal state in 1848. Some territorial disputes remained, and were resolved in the 1850s and 1860s. Since then, the territory of Switzerland has remained fixed (with the exception of minor border corrections) by 1863. There have since been a number of unsuccessful suggestions for further enlargement. The most realistic of these was the possible accession of Vorarlberg following a referendum held there in 1919, in which 81% of the people of Vorarlberg voted to join Switzerland; but Vorarlberg was instead incorporated into the First Austrian Republic. There was a brief and unsuccessful revival of Alemannic separatism after World War II, and in the later half of the 20th century, there were no serious political scenarios of any further enlargement of Switzerland. Since 2008, similar proposals have once again been discussed, at least as hypotheticals, as expressions of Euroscepticism, reflecting the wish of territories within European Union member states to leave the European Union. Since there is currently no legal framework governing the admission of new cantons, any enlargement would, as a matter of Swiss law, require an amendment of the Swiss federal constitution and therefore a national popular referendum. A corresponding proposal was submitted by Jurassian representative Dominique Baettig in 2010, but was dropped after Baettig was not re-elected in 2011. Old Swiss Confederacy Switzerland, a multilingual federation of 26 cantons whose origins lie in a defensive alliance of alpine valleys around the end of the 13th century, grew through the accession of new states and territories during the 14th to 16th centuries. The accession of Appenzell in 1513 completed the growth of the Confederacy into