There are today 25 countries in the world (out of the 193) that are federal, some of them since several centuries ago. The oldest federation is the United States of America, dating back since 1789, followed by Venezuela (1811) and Switzerland (1848), while the newest is South Africa (1996). Nevertheless, these 25 countries are the most populous and with the largest territories. Today, 40% of the world’s population lives in federal states.