Progress during the Last Half-Century of Spanish Rule.--We have now come to the last half-century and to the last phase of Spanish rule. In many respects this period was one of economic and social progress, and contained more of promise than any other in the history of the Islands. During this last half-century the Spanish rulers had numerous plans for the development and better administration of the Philippines, and, in spite of a somewhat wavering policy and the continual sore of official peculation, this was a period of wonderful advancement. Revolution and separation from Spain came at last, as revolutions usually do, not because there was no effort nor movement for reform, but because progress was so discouragingly slow and so irritatingly blocked by established interests that desired no change. Effect of Opening the Port of Manila to Foreign Trade.--Increase in Agriculture.--The opening of the port of Manila to foreign trade, in 1837, was followed by a period of rising industry and prosperity. Up to this time the archipelago had not been a producing and exporting country, but the freeing of trade led to the raising of great harvests for foreign export, which have made world-wide the fame of certain Philippine productions. Chief among these are of course Manila hemp and tobacco. These were followed by sugar and coffee culture, the latter plant enriching the province of Batangas, while the planting of new cocoanut groves yearly made of greater importance the yield of that excellent product, copra. These rich merchandises had entered very little into commerce during the early decades of the century. Increase in Exports.--In 1810 the entire imports of the Philippines amounted in value to 5,329,000 dollars, but more than half of this consisted of silver sent from Mexico. From Europe and the United States trade amounted to only 175,000 dollars. The exports in the same year amounted to 4,795,000 dollars, but a million and a half of this was Mexican silver exported on to China, and the whole amount of exports to Europe and the United States was only 250,000 dollars. In 1831 the exportation of hemp amounted to only 346 tons. But the effect upon production of opening Manila to foreign trade is seen in the export six years later of 2,585 tons. By 1858 the exportation of hemp had risen to 412,000 piculs, or 27,500 tons. Of this amount, nearly two thirds, or 298,000 piculs, went to the United States. At this time the North Atlantic seaboard of America was the center of a most active ship-building and ship-carrying trade. The American flag was conspicuous among the vessels that frequented these Eastern ports, and "Manila hemp" was largely sought after by American seamen to supply the shipyards at home. Of sugar, the export in 1858 amounted to 557,000 piculs, of which more than half went to Great Britain.