 Tucumán is the most densely populated (with 60 inhabitants/km2, the only Argentine province more densely populated than the world average), while the southern province of Santa Cruz has less than 1 inhabitant/km2.In the mid-19th century, a large wave of immigration started to arrive to Argentina due to new Constitutional policies that encouraged immigration, and issues in the countries the immigrants came from such as wars, poverty, hunger, famines, pursuit of a better life, among other reasons.The main immigration sources were from Europe, the countries from the Near and Middle East, Russia and Japan.