Factors Contributing to Urbanization in Late 19th Century America

In the late 19th century, the rapid urbanization of American cities was influenced by various social, economic, and technological factors. As millions of Americans flocked to cities for jobs and opportunities, this urban shift also brought about significant challenges. These challenges included overcrowded living conditions, public health concerns, and the rise of social reform movements aimed at addressing the needs of impoverished urban populations. Which of the following developments primarily contributed to the urbanization process during this period?