Omaha is the most populous city in the U.S. state of Nebraska. It is located in the Midwestern United States along the Missouri River, about 10 mi (15 km) north of the mouth of the Platte River. Omaha had a population of 486,051 at the 2020 census, making it the 41st-most populous U.S. city. The eight-county Omaha–Council Bluffs metropolitan area extending into Iowa has approximately 1 million residents, the 55th-largest metropolitan area in the U.S. Omaha is the county seat of Douglas County.
Omaha's pioneer period began in 1854, when the city was founded along the Missouri River by speculators from neighboring Council Bluffs, Iowa. It originally comprised a crossing called Lone Tree Ferry earning the city its nickname, the "Gateway to the West". Omaha introduced this new West to the world in 1898, when it played host to the World's Fair, dubbed the Trans-Mississippi Exposition. During the 19th century, Omaha's central location in the United States spurred the city to become an important national transportation hub. Throughout the rest of the 19th century, the transportation and jobbing sectors were important in the city, along with its railroads and breweries. In the 20th century, the Omaha Stockyards, once the world's largest, and its meatpacking plants gained international prominence.