On July 26, 1788, New York ratified the U.S. Constitution, becoming America’s 11th state. Two of the most powerful Indian groups in North America lived in New York, the Algonquian family and the Iroquois. These tribes were large and well organized, especially the Iroquois. The Iroquois federation was the most efficient North American Indian government. Giovanni da Verrazzano, an Italian explorer sailing for France, was probably the first European to reach New York in 1524. Henry Hudson, an Englishman serving the Dutch, sailed up the Hudson River in 1609. His exploration gave the Netherlands rights to the territory of much of New York, New Jersey, Delaware, and part of Connecticut. The Dutch called this land New Netherland. In 1609, the French explorer Samuel de Champlain entered the northern portion of New York, claiming that area for his country.