the rebuilding and dramatic expansion of railroads throughout the South; they were modernized in terms of rail gauge, equipment and standards of service. the Southern network expanded from in 1870 to in 1890. Railroads helped create a mechanically skilled group of craftsmen and broke the isolation of much of the region. Passengers were few, however, and apart from hauling the cotton crop when it was harvested, there was little freight traffic. The lines were owned and directed overwhelmingly by Northerners, who often had to pay heavy bribes to corrupt politicians for needed legislation. The Panic of 1873 ended the expansion everywhere in the United States, leaving many Southern lines bankrupt or barely able to pay the interest on their bonds. Backlash to Reconstruction Reconstruction was a harsh time for many white Southerners who found themselves without many of the basic rights of citizenship (such as the ability to vote). Reconstruction was also a time when many African Americans began to secure these same rights for the first time. With the passage of the 13th Amendment to the Constitution (which outlawed slavery), the 14th Amendment (which granted full U.S. citizenship to African Americans) and the 15th Amendment (which extended the right to vote to black males), African Americans in the South began to enjoy more rights than they had ever had in the past. A reaction to the defeat and changes in society began immediately, with vigilante groups such as the Ku Klux Klan arising in 1866 as the first line of insurgents. They attacked and killed both freedmen and their white allies. By the 1870s, more organized paramilitary groups, such as the White League and Red Shirts, took part in turning Republicans out of office and barring or intimidating black people from voting. Early Rural South Agriculture's share of the labor force by region, 1890: The South remained heavily rural until World War II. In the decades before the 1940s, there were only a few scattered large cities in the region, with small courthouse towns serving the mostly rural population. Local politics revolved around the politicians and lawyers based at the courthouse. Mill towns, primarily focused on textile production or tobacco product manufacture, began opening in the Piedmont region, especially in the Carolinas. Racial segregation and outward signs of inequality were commonplace in many rural areas and rarely challenged. Blacks who violated the color line were liable to expulsion or