Why did anti slavery and pro slavery groups encourage people to move to kansas nebraska/?

The Kansas-Nebraska Act of 1854 called for ''popular sovereignty''. The decision about slavery was to be made by the settlers in Kansas rather than by outsiders. The decision as to whether Kanas would become a free state or a slave state would be decided by the votes of people in Kansas. Which ever side had more votes counted by officials would decide if Kansas would become a free state or a slave state.