Unusual conditions, political, economic, and religious, have, however, from time to time caused Hollanders to emigrate to foreign lands, and during the decade 1840-50 many set sail for the United States. After the fall of Napoleon the Netherlands had changed from a republican to a limited monarchical form of government. Belgium reunited with Holland under the name of Kingdom of Netherlands, with William I, son of the former Dutch stadtholder, as king. The union was not successful, and the rebellion of 1830, which resulted in the separation of Holland and Belgium, necessitated large armies which William I kept up for years in the hope of reconquering Belgium. Then in 1825 an inundation of the ocean swept away the dikes, devastated the land, and left thousands homeless and without resources. With the abdication of William I and the accession of his son, William II, conditions did not improve. War and flood turned the thoughts of the suffering lower and middle classes to emigration, and the period from 1840 to 1850 saw the great exodus of Dutch to America. [Illustration: PETER DAAN Pioneer Dutch Settler in Oostburg, Sheboygan County, Wisconsin] Religious difficulties arising at this time also caused the emigration of several distinct groups. With the separation of Holland from Spain came separation from the civil and religious rule of the Catholic Church and the adoption of the Reformed Church by the State. The Dutch Reformed Church was Calvinistic in doctrine and Presbyterian in government. German philosophy and French liberalism gradually influenced the lives of members of the State Church; and the monarch and other governmental officers being friendly toward the new thought, the church synods permitted certain changes in the service and doctrine. Again and again the orthodox party tried to overthrow the new order, and after many failures in such attempts left the established church to form a separate ecclesiastical body called the Free Separate Reformed Church. The civil government, fearing that civil revolution would follow this religious upheaval, opposed the new church, forbade meetings, and fined ministers. With the accession of William II the organization was recognized as a corporate body, but many restrictions were imposed upon it and financial aid, granted other denominations, was refused it. A large number of the Separatists gladly accepted the terms imposed, but others, smarting under the restrictions and foreseeing no relief in the near future, resolved to emigrate to America. Three separate parties, each under a prominent minister, were formed for the purpose of founding settlements in the United States. Rev. R. C. Van Raalte led his people to the eastern shore of Lake Michigan, where they founded settlements which later came to be among the prosperous communities of Michigan. Among them are Holland, where Hope College was founded, Grand Haven, Muskegon, and Grand Rapids.