The type, though originating in Baltimore, was not developed there to its ultimate capacity, but the idea was taken up by Philadelphia, New York, and New England ship-builders and embodied in the famous lines which plied between this country and the Pacific Ocean. The discovery of gold in California also gave a great impetus to commerce in sailing-vessels. Of course, steamships soon began to run from New York to the Atlantic side of the Isthmus and from the Pacific side to San Francisco, but there was no railway across the Isthmus at first, so that very little freight traffic could be handled by these steamers. The result was that all freights between the Atlantic coast and California had to go around Cape Horn, and in this traffic the clipper ship fully asserted its value. The decade of the 50’s was really the zenith of the American carrying trade on the ocean. Relatively to the total amount of ocean commerce, our ships carried a larger proportion of it than ever before in time of peace. Of course, during the Napoleonic wars, when our flag was neutral, we carried a larger proportion of our own products than in the 50’s, but never before in a time of general peace. The Crimean War, which happened during this period, also helped American commerce in the ocean carrying trade, because the French and English took up a great deal of their tonnage for transporting troops and military supplies during the years 1854, 1855, and 1856, and to a great extent the places of these ships were filled by vessels under the American flag. All these causes combined to create marked activity in American ship-building. To this might be added the effort to establish a trans-Atlantic steamship line under the American flag in opposition to the heavily subsidized Cunard Line. This was known as the Collins Line, and while the government aid lasted it held its own in competition with its British antagonists, but the subsidy was soon withdrawn, and with it the Collins Line collapsed.