People flocked to the cities in the late 1800's because during this time factories were booming and there was more opportunity in the cities. Therefore the answer is B.
The answer is "The Kansas-Nebraska Act".
<span>Senator
Stephen Douglas was the person who introduced a bill in January 1854. This separated
the land situated in the west of Missouri into Kansas and Nebraska. After much deliberation
the act was passed on 30 May 1854 by the Congress as The Kansas-Nebraska Act. It allowed the territories to decide if they would allow
slavery in their territories or not.</span>
