History of Nebraska

The history of the U.S. state of Nebraska dates back to its formation as a territory by the Kansas-Nebraska Act, passed by the United States Congress on May 30, 1854. The Nebraska Territory was settled extensively under the Homestead Act of 1862 during the 1860s, and in 1867 was admitted to the Union as the 37th U.S. state. The Plains Indians were descendants of succeeding cultures of indigenous peoples who have occupied the area for thousands of years.

During the Late Cretaceous, between 66 million to 99 million years ago, three-quarters of Nebraska was covered by the Western Interior Seaway, a large body of water that covered one-third of the United States. The sea was occupied by mosasaurs, ichthyosaur, and plesiosaurs. Additionally, sharks such as Squalicorax, and fish such as Pachyrhizodus, Enchodus, and the Xiphactinus, a fish larger than any modern bony fish, occupied the sea. Other sea life included invertebrates such as mollusks, ammonites, squid-like belemnites, and plankton. Fossil skeletons of these animals and period plants were embedded in mud that hardened into rock and became the limestone that appears today on the sides of ravines and along the streams of Nebraska.

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