Cheyenne County and Sidney grew out of the westward push of the transcontinental railroad in 1867, though the region had earlier been crossed by frontier trails tied to the Oregon, Mormon, Overland, Emigrant Road, Pole Creek Crossing, and Texas cattle traffic, and had also been a place of Native American battles, the open prairie cattle industry, the Pony Express, and trading posts. Early Cheyenne County covered the south half of the Nebraska Panhandle, while the unorganized north half was attached to it for judicial and legal business, and Sidney served as territorial capital and county seat for the larger area until additional counties were carved from it beginning in 1885. To protect Union Pacific builders, soldiers were stationed along Lodge Pole Creek on April 29, 1867, and an army post first known as Sidney Barracks and later Fort Sidney was established, later relocated in 1871 and operated until 1894. Sidney became famous from 1874 to 1883 as the eastern end of the 267-mile Sidney-Deadwood Trail after gold was discovered in Dakota Territory, and after H.T. Clarke built a toll bridge over the North Platte River in 1876 the route carried more than 100 million pounds of registered freight, while a major gold bullion robbery near the U.P. Freight House on March 10, 1880 went unsolved. In the same years Sidney gained a national reputation for lawlessness, with frequent hangings, a vigilante roundup of outlaws on April 1-4, 1881, more than 80 saloons, gaming halls, and brothels on Front Street, over 1,000 criminal cases, and 56 known murders or attempted murders prosecuted from 1876 to 1881, earning it such nicknames as Sinful Sidney and Toughest Town on the Tracks. The Homestead Act of 1862 and the Kincaid Act of 1904 later opened land to settlers, and with a major land office nearby Sidney remade itself from the 1880s through the 1940s as a farming and ranching trade center along the Lincoln Highway and Lodge Pole Creek valley, becoming Nebraska's leading winter wheat producing county. During World War Two, the Sioux Ordnance Depot, commissioned in 1942 just northwest of Sidney, employed more than 2,000 people through 1967, and oil discovered north of Sidney in 1949 launched a long oil and gas boom that helped keep Cheyenne County among Nebraska's leading producing counties. In the 1960s Cheyenne County also became home to 38 Minuteman missile bases in the Warren Air Force Base complex, and on October 19, 1974, Sidney was the site of Interstate 80's golden link joining the highway from New York to San Francisco. After economic setbacks from the depot closure, the end of missile construction, oil depletion, railroad job transfers, and changes in agriculture, Sidney renewed growth by extending utilities to Exit 59 in 1987, building on its highways, railroads, airport, industrial parks, and business development, and in 2004 it was named one of America's Top 100 Rural Communities under 50,000 population.