Towards the end of the 19th century, San Marino experienced economic depression: a large increase in the birth rate coupled with a widening of the gap between agricultural and industrial development led people to seek their fortunes in more industrialised countries. The Sammarinese first sought seasonal employment in Tuscany, Rome, Genoa and Trieste, but in the latter half of the century whole families were uprooted, with the first permanent migrations to the Americas (United States, Argentina and Uruguay) and to Greece, Germany and Austria. This phenomenon lasted up to the 1870s, with a pause during the First World War and an increase during the Fascist period in Italy. Even today there are still large concentrations of San Marino citizens residing in foreign countries, above all, in the United States, in France and in Argentina. There are more than 15,000 San Marino citizens spread throughout the world.