Although intended to win national support for douglas's vision of a transcontinental railroad, the kansas-nebraska act sacrificed the antislavery provisions of the

The correct answer is the Missouri Compromise.

The Kansas-Nebraska Act implemented the concept of popular sovereignty, meaning that the citizens had the ability to vote on whether or not they wanted the institution of slavery. This ability for the citizens to choose disregards the Missouri Compromise, which stated that any territory above the 36'30 line would be free from slavery. Even though both states are above this line, they can become slave states if their citizens vote for it.