<P> Silver and gold from the viceroyalty of Peru were transported overland across the isthmus by Spanish Silver Train to Porto Bello, where Spanish treasure fleets shipped them to Seville and Cádiz from 1707 . </P> <P> Lionel Wafer spent four years between 1680 and 1684 among the Cuna Indians . </P> <P> Scotland tried to establish a settlement in 1698 through the Darien scheme . </P> <P> The California Gold Rush, starting in 1849, brought a large increase in the transportation of people from the Atlantic to the Pacific . Steamships brought gold seekers from eastern US ports who trekked across the isthmus by foot, horse, and later rail . On the Pacific side, they boarded Pacific Mail Steamship Company vessels headed for San Francisco . </P>

Why did ocean circulation patterns change in the atlantic 3 million years ago