The U.S. originated as colonies of a global empire. It won its independence with the help of foreign powers that intervened with money, weapons, and troops. French soldiers and warships helped General Washington win at Yorktown, and the Spanish siege of Gibraltar played its part as well. War and diplomacy paved the way west for the new United States. By the end of the 19th Century, the U.S. was the largest industrial economy in the world, which gave it the means to become the Arsenal of Democracy and leader of the Free World in the 20th Century, beating back the...