Desoto National Wildlife Refuge. The jobbing and wholesaling district brought new jobs, followed by the railroads and the stockyards. Groundbreaking for the First transcontinental railroad in 1863, provided an essential developmental boom for the city. In 1862, the U.S. Congress allowed the Union Pacific Railroad to begin building westward railways; in January 1866 it commenced construction out of Omaha. The Union Stockyards, another important part of the city's development, were founded in South Omaha in 1883. Within 20 years, Omaha had four of the five major meatpacking companies in the United States. By the 1950s, half the city's workforce was employed in meatpacking and processing. Meatpacking, jobbing and railroads were responsible for most of the growth in the city from the late 19th century through the early decades of the 20th century. Immigrants soon created ethnic enclaves throughout the city, including Irish in Sheelytown in South Omaha; Germans in the Near North Side, joined by the European Jews and black migrants from the South; Little Italy and Little Bohemia in South Omaha. Beginning in the late 19th century, Omaha's upper class lived in posh enclaves throughout the city, including the south and north Gold Coast neighborhoods, Bemis Park, Kountze Place, Field Club and throughout Midtown Omaha. They traveled the city's sprawling park system on boulevards designed by renowned landscape architect Horace Cleveland. The Omaha Horse Railway first carried passengers throughout the city, as did the later Omaha Cable Tramway Company and several similar companies. In 1888, the Omaha and Council Bluffs Railway and Bridge Company built the Douglas Street Bridge, the first pedestrian and wagon bridge between Omaha and Council Bluffs. Gambling, drinking and prostitution were widespread in the 19th century, first rampant in the city's Burnt District and later in the Sporting District. Controlled by Omaha's political boss Tom Dennison by 1890, criminal elements enjoyed support from Omaha's "perpetual" mayor, "Cowboy Jim" Dahlman, nicknamed for his eight terms as mayor. Calamities such as the Great Flood of 1881 did not slow down the city's violence. In 1882, the Camp Dump Strike pitted state militia against unionized strikers, drawing national attention to Omaha's labor troubles. The Governor of Nebraska had to call in U.S. Army troops from nearby Fort Omaha to protect strikebreakers for the Burlington Railroad, bringing along Gatling guns and a cannon for defense. When the event ended, one man was dead and several were wounded. In 1891,