John Baily was an Englishman who lived for many years in Central America. He was employed in 1837-38 by the government of Nicaragua to survey a potential canal route from the Caribbean Sea to the Pacific Ocean. This map, published in London in 1850, was accompanied by a book, Central America, published separately, which contained much of the detailed information that Baily gathered to make this map. The map shows four possible canal routes: one surveyed for the government of Costa Rica in 1848 by the Danish engineer Andres Oersted, Baily’s own proposed route of 1837-38, a route across present-day Panama proposed in 1844 by the French engineer Napoleon Garella, and a route across Nicaragua favored by Prince (and later Emperor) Louis Napoleon of France. The drawings at the lower left highlight the engineering challenges posed by building a canal that would have to traverse inland hills and mountains and account for the different sea levels (caused by tides) on the Atlantic and Pacific sides of the canal. Baily’s map and writings frequently were cited in later debates about where and how the canal should be built.