Americans created their Revolution and government on popular sovereignty. In the 1850s Popular sovereignty in the United States meant a very controversial way to deal with slavery in the territories. This was pushed by senator Stephen A. Douglas. It meant that people living in a territory would be the ones to decide if slavery would be allowed. It led to fighting in Bleeding Kansas. This was because abolitionists (people who didn't want slavery) and pro-slavery people came to the Kansas territory in order to decide the elections. 