In 1840, Matthew Fontaine Maury became the first superintendent of the US Naval Observatory, where he began his life's work mapping the great ocean routes & providing sailing directions for navigators the world over. This book uses his career as a window on 19th-century maritime history: the ascendancy of the US as a maritime power; the brief, but glorious, clipper-ship era of the 1850s; the rise of steam & steel; & the Civil War & the destruction of the US merchant fleet.