During the two decades preceding the abolition law of 1880, Cuban sugar planters pursued two parallel goals. The first undertaking was a concerted effort to increase the efficiency of agricultural and industrial production. A sophisticated railroad network was constructed to the interior from the ports of Havana, Matanzas, Cárdenas, and Cienfuegos in the 1840s and 1850s. Railroads opened high-yielding virgin land in frontier regions to production, and in the 1860s and 1870s, planters attempted to further the transportation revolution by developing rail systems within their estates to carry cane from fields to mills. Because the sucrose content of cane begins to drop immediately after the cane is cut, internal railway lines had the potential to revolutionize sugar production by moving cane quickly to the processing phase. Railroads also helped to resolve the recurring problem of roads washed out by heavy rains, which often precluded transporting harvested cane to mills for refining. In addition to revolutionizing transportation, planters also sought to raise industrial yields by installing modern milling equipment with greater processing capacity. The Jamaican trains of the early nineteenth century were replaced by vacuum-pan evaporators and centrifuges on the most modern mills by the 1860s and 1870s, a change that produced higher grades of sugar more efficiently.