A chart made by Lieutenant M. F. Maury (1806-1873) to accopmany a report by the U.S. House of Representatives concerning "steam communication with China and the Sandwich Islands", that is, Hawaii.

The 36 page report was delivered to Congress on May 4, 1848 by the chairman of the Committee of Naval Affairs, T. Butler King. King explained that by expanding America's naval presence across the Pacific, the United States would be 'in a position to extend our view across the bosom of that broad ocean to the shores of Japan and China, and to consider what other and further measures may be adopted for the encouragement and protection of our commerce in that portion of the globe'. Later in the report, King claims that 'by an examination of the chart, it will be perceived that either Monterey or San Francisco must become the port of departure for China, as being situated almost immediately on the route from Panama'. At this time, San Francisco harbour was experiencing a great influx of ships, with people flocking to California in search of gold, and the port would soon be expanded. On the present chart, however, the routes crossing the Pacific stretch from Monterey Bay; while those stretching to South East Asia following straight lines, the two routes passing through Japan curve over the top of the Pacific Ocean. King's report unpacks these two new routes, one of which had been proposed by Lieutenant Maury himself; he explains that 'the chart which is attached to and forms part of this report shows the courses and sitances across the Pacific on the two routes, and the advantages of the great circle'. Although these routes and trade with East Asia are the focus of King's report, various other lines on the map identify shipping routes across the entire globe, demonstrating the expansion of American trade in the mid-nineteenth century. Lieutenant Maury had served in the U.S. Navy since the age of 19, but after an injury left him unable to perform his duties, he took to studying the ocean, meteorology and hydrography. He eventually became Superintendent of the U.S. Naval Observatory and head of the Depot of Charts and Instruments. In this role he published a vast number of charts, treatise and manuals for the use of American sailors, and died at the age of 67 after completing a national lecture tour on the subject of weather forecasting.