The defense of America's seacoast has been one of the key concerns since the earlier years of the Republic. American coast defense steadily evolved through the age of muzzle loading cannon, ever larger breech loading weapons, and finally to the culmination in large, long range guns capable of targeting the largest and most heavily armed warships of their age. By the end of World War II, the United States had some of the strongest defenses in the world. Given the importance of the US naval bases around Norfolk, Virginia and the shipyards of Hampton Roads, the seacoast defenses protecting Chesapeake Bay contained the largest collection of firepower in the continental United States as they reached their apex during World War II.