The article analyses the genesis of federalism in the context of European and American history, and the practical relevance of federalism to modern Europe. The Swiss Confederation was the first experience of unification of diverse regions with common development goals (defense from neighbors) and the rules of conduct. At the same time, the Swiss cantons retained sovereignty and priority of its legislation. This experience was used in the creation of the United States. According to the constitution, the United States became a sovereign federation, in which the central law dominates over the states' law and the principle of territorial organization of the federation. The American experience was used in the 19 century by Switzerland, which created a multinational federation with a strong center, organized on a national and on a territorial basis. The positive experience of federalism in the 20 century was enforced in post-war Germany. At the same time, the simulation of federation in Czechoslovakia and Yugoslavia led these states to collapse. The reasons that the author considers are the national basis of the federation and too much regional power. Special attention is paid to the development of federalism in the USSR and Russia. Author classifies the Soviet Union as a communist confederacy and notes that the features of this model were taken over by Russia. The reform of federalism, conducted under president V. Putin, significantly increased degree of stability.