Final answer:
The railroad had a significant impact on the Kansas-Nebraska Act. It played a role in the passage of the act, as it was proposed to facilitate the completion of a national railroad through Chicago. Additionally, the presence of the railroad in the territories had economic implications and contributed to the violent confrontations in Kansas.
Step-by-step explanation:
The impact of the railroad on the Kansas-Nebraska Act was significant. The act itself, passed in 1854, allowed for the creation of the Kansas and Nebraska territories, and applied the principle of popular sovereignty, which meant that the residents of these territories would decide whether to adopt slavery. The railroad played a role in the passage of the act as it was proposed by Stephen Douglas to facilitate the completion of a national railroad that would pass through Chicago.
Moreover, the presence of the railroad in the newly-created territories had economic implications. The railroad would attract settlers, create jobs, and promote economic growth in the region. It also contributed to an influx of migrants to Kansas, who sought to either protect or stop the spread of slavery, leading to violent confrontations.