In 1492, Christopher Columbus sailed west and reached islands in the Caribbean. He claimed the land for Spain. But Portugal had been exploring the coast of Africa for decades. Both countries wanted to control new trade routes and territories. The argument got so heated that the Pope stepped in. On June 7, 1494, Spain and Portugal signed the Treaty of Tordesillas. The deal drew an imaginary line through the Atlantic Ocean. Spain received rights to almost all land west of the line. Portugal received rights to land east of it. The line ran through what is now eastern Brazil. That is why Brazilians speak Portuguese today while most of South America speaks Spanish. Neither country asked the indigenous people already living on these lands. Millions of people had built cities, farmed fields, and created rich cultures long before any European ships arrived. The treaty treated entire continents as empty property to be divided. The agreement shaped the map of the Americas for centuries. It determined which languages, laws, and customs would be brought to different parts of the Western Hemisphere.