The history of South America is the study of the past, particularly the written record, oral histories, and traditions, passed down from generation to generation on the continent in the Earth's western hemisphere and (chiefly) southern hemisphere. South America has a history that spans a wide range of human cultural and civilizational forms. While millennia of independent development were interrupted by the Portuguese and Spanish colonization drive of the late 15th century and the demographic collapse that followed, the continent's mestizo and indigenous cultures remain quite distinct from those of their colonizers. Through the trans-Atlantic slave trade, South America (especially Brazil) became the home of millions of people in the African diaspora. The mixing of races led to new social structures. The tensions between colonial countries in Europe, indigenous peoples and escaped slaves shaped South America from the 16th through the 19th Centuries.