For fully ten years there had been ever-increasing excitement over the question of the limitation or the extension of slavery.

This had clearly become the topic of supreme interest throughout the country, and yet the two leading parties avoided the issue.

Their own membership was divided.
Northern Democrats, many of them, were decidedly opposed to slavery extension.

Southern Whigs with equal intensity favored the extension of slavery into the new territory.

The platforms of the two parties were silent on the subject.