It was first promoted in the 1840s. Stephen A. Douglas, one of the sponsors of the Kansas–Nebraska Act inserted it in the new law as a measure to balance slave and free states. Abraham Lincoln was one of those who did not agree. He thought Congress should regulate federal territories. The act was passed but popular sovereignty proved to have deadly consequences. When Kansas was being considered for statehood, there was a rush by both people who were for and against slavery to go to Kansas and vote on the issue of slavery. This resulted in a great deal of fraud and violence. It led directly to Bleeding Kansas, the bloody border war over slavery.