Answer the question: According to TedEd, what was the one piece of legislation that divided the nation?

The Kansas-Nebraska act of 1854 was a proposed by Stephen A. Douglas . It was a bill that would divide a large chunk of incorporated land into two organized territories, Nebraska and Kansas.

Explanation:

Although its proponents tried to infer that the bill was to protect the political rights of settlers since it allowed the residents of the territories under question to vote if whether or not to allow slavery in their borders , the bill more or less, angered off the Anti-Slavery Northerners because it repealed the Missouri Compromise of 1820.

That Compromise wanted to balance the number of Pro-Slavery and Anti-Slavery states of the U.S.

For Douglass, the Kansas-Nebraska act would allow him to build the Transcontinental Railroad he promoted while (as the believer of popular sovereignty as he was, and because he wanted to warm up to the Southern Politicians who he'll need support from if he wanted to build his railroad) allowing the people of those territories to vote for Slavery or No Slavery.

The Kansas-Nebraska Act was also one of the causes of the American Civil War.