the Delaware River, and the Hudson River attracted diverse business. Fur trappers moved along these rivers, and there was enough flow to enable milling with water wheel power. Industry Abundant forests attracted both the lumbering and shipbuilding industries to the Middle Colonies. These industries, along with the presence of deep river estuaries, led to the appearance of important ports like New York and Philadelphia. While the Middle Colonies had far more industry than the Southern Colonies, it still did not rival the industry of New England. In Pennsylvania, sawmills and gristmills were abundant, and the textile industry grew quickly. The colony also became a major producer of pig iron and its products, including the Pennsylvania long rifle and the Conestoga wagon. Other important industries included printing, publishing, and the related industry of papermaking. Politics The Middle Colonies' political groups began as small groups with narrowly focused goals. These coalitions eventually grew into diverse and large political organizations, evolving especially during the French and Indian War. The Middle Colonies were generally run by Royal or Proprietary Governors and elected Colonial Assemblies. Many Middle Colony constitutions guaranteed freedom of religion and forbade taxation without representation. Royal governors were arrested or overthrown on more than one occasion, most notably when New Jersey arrested its governor and during Leisler's Rebellion in New York. Growing unrest in the Middle Colonies eventually led the region to become the meeting place for the Continental Congress, and a center for revolution. However, there were numerous pockets of neutrals and Loyalists. Demographics The Middle Colonies tended to mix aspects of the New England and Southern Colonies. Landholdings were generally farms of , owned by the family that worked it. In New York's Hudson Valley, however, the Dutch patroons operated very large landed estates and rented land to tenant farmers. Ethnically, the Middle Colonies were more diverse than the other British colonial regions in North America and tended to be more socially tolerant. For example, in New York, any foreigner professing Christianity was awarded citizenship, leading to a more diverse populace. As a consequence, early German settlements in the Americas concentrated in the Middle Colonies region. Indentured servitude was especially common in Pennsylvania, New Jersey, and New York in the 18th century, though fewer worked in agriculture. German immigrants favored the Middle Colonies. German immigration greatly increased around 1717, and many immigrants began coming from the Rhineland. They were erroneously