What problem arose as a result of the railroads that were built in the mid-19th Century?

The Industrial Age brought many changes to American life. The changes were so rapid and widespread that many church leaders became deeply concerned about the effects of industrialization on society and their congregations. During the second half of the Nineteenth Century, the Second Great Awakening began as Protestant ministers began to preach for the improvement of the condition of industrial society through charity and justice. This movement, known as the Social Gospel, was led by Washington Gladden and Lyman Abbott. Their goal was to join salvation to good works. These ministers wanted people to put aside all earthly belongings and help those in need. They taught that the purpose of wealth was to help the less fortunate, and the principles of a just society were egalitarian in nature.

The Social Gospel Movement directly influenced the creation of what group in the United States?