Called 'the greyhounds of the sea,' clippers were the fastest wind-powered ships ever. Traveling over 2,000 miles within a week, the 19th-century clippers brought the world back to American shores.Called 'the greyhounds of the sea,' clippers were the fastest wind-powered ships ever. Traveling over 2,000 miles within a week, the 19th-century clippers brought the world back to American shores.