2. One of the negative effects the Spanish and Portuguese had on the development of was the introduction of diseases that killed large numbers of Indians. *​

Tropic of cancer and tropic of capricorn

The first immigrants to settle in what is now the united states were the ancient ancestors of modern native americans. the precise routes of those first north american immigrants are disputed, but there is no uncertainty about the fact that every human being on the continent is either a recent immigrant or a descendant of earlier immigrants. since the first immigrants came here from asia more than thirteen thousand years ago, there have been four large and easily recognizable modern waves of immigrants into the united states.