Globalization began with ancient silk and spice trade routes connecting Asia, Europe, and Africa from the 1st century BC through the 15th century. The Age of Discovery from the 15th to 18th centuries expanded global trade, with Columbus' voyage to America ending pre-Colombian civilizations in the Americas. The first wave of modern globalization in the 19th century was driven by British industrial and imperial dominance using new technologies like steam engines. Major infrastructure projects further connected the world economically until World War I halted globalization. It resumed after World War II under US leadership through industries like automobiles and air travel, becoming truly global after the fall of the Iron Curtain in 1989. Globalization is now entering a fourth,