The westward expansion of the United States, which took place between 1763 and 1890, is at once one of the most romantic sagas of human accomplishment and one of the bleakest tragedies of human cruelty. In just over one century, American settlers, soldiers, and diplomats helped the United States expand from a mere thirteen British colonies clinging to the eastern seaboard to a sprawling nation stretching 3,000 miles from the Atlantic to the Pacific Oceans.