Why didn't Americans come in ancient times?

In ancient times, traffic conditions were backward and shipping was underdeveloped, so 1776 established the United States.

Before Columbus discovered the new American continent, the United States was a wild land, and it was only 238 years since 1776 was founded. Compared with other countries in the world, the United States is a country without history.

North America was originally inhabited by Indians. /kloc-at the end of 0/5, Spain, the Netherlands and other countries began to immigrate here, and Britain came from behind. 1773, Britain has established 13 colonies. 1775, the American people's war of independence against the British colonists broke out. 1776 On July 4th, the Second Continental Congress was held in Philadelphia, with George Washington as the commander-in-chief, and adopted the Declaration of Independence, officially announcing the establishment of the United States of America. On 1788 after the War of Independence, George Washington was elected as the first president of the United States. After the Civil War, the American capitalist economy rose rapidly. /kloc-at the beginning of the 0/9th century, the United States began to expand abroad. After World War II, the United States greatly increased its national strength and became the only hegemonic superpower in the world today.