The dynamic process of commercial expansion, dramatic technological change, and outsized accomplishment gave rise to an outlook known as Manifest Destiny, the dominant ideology of the period 1815-61. Any history of the antebellum American Empire between the end of the War of 1812 and the beginning of the Civil War must emphasize the critical importance of cotton. The explosion of cotton production and its importance to national prosperity were boosted by revolutionary developments in transportation and communication. The creation of an American empire of commerce depended upon the creation of an American empire of the seas. American whaling reached the peak of its profitability in the 1850s, before new sources of lamp oil and the Civil War decimated the fleet. The origin of the American missionary movement is to be found in a prophetic vision experienced by a Massachusetts college student. Americans missionaries and whalers came together to secure the Hawaiian Islands as an American outpost.