Sea of Glory, by Nathaniel Philbrick.
http://www.amazon.com/Sea-Glory-Disc...3715733&sr=8-1
The story of The U.S. Exploring Expedition (1838-1842). The search of the Southern Hemisphere for new lands (mostly in the Pacific Ocean). It similar to the Lewis and Clark Expedition (I prefered Stephen Ambrose's, Undaunted Courage) except on a broader scale. I am only a third of the way through, but it is very good.
Philbrick also wrote the excellent, In the Heart of the Sea. The story of the whaleship Essex, which was also a good read.