 During the 19th century, the favorite destinations of migrants were the French colonies and South America (for more details, see Corsican immigration to Puerto Rico and Corsican immigration to Venezuela).Then, between the 1920s and the 1950s, the major destination became the French mainland (primarily Marseille, today considered as the "first Corsican city of the world" with a number around 200,000).Causes of this emigration are various; poverty is the main reason (the French laws for restriction of exportations, the Second Industrial Revolution and the agricultural crisis had an adverse effect on the local economy).