Some historians claim that the mistakes of a "blundering generation" of political leaders led, by 1860, to the imminent breakup of the union. using the events from "politics and power" on the thematic timeline on page 409, explain why you agree or disagree.

Completely agree, the political divisions resulted in the break-up of the union, the ideas and opposing positions promoted the sectarianism that led to the enactment of laws, such as the Kansas-Nebraska law that generated serious conflicts that led to the war of secession in 1861, the separation was so strong that divided consolidated parties like the Whig Party, making of it, two sides against each other. 

The answer is option b and c.