European countries colonized other lands like the Americas in the 1500s due to declining natural resources and overpopulation in Europe. This allowed colonists from countries like England, France, Portugal, and Spain to gain new lands and opportunities, but resulted in the genocide, enslavement, and displacement of millions of Native Americans. The European colonization of the Americas was one of the bloodiest and most horrific periods in human history due to the immense suffering inflicted upon indigenous populations through violence, slavery, and loss of their homelands.