Why did Stephen Douglas want the Kansas-Nebraska Territory organized?

He wanted to protect Northerners from attacks by settlers.

He wanted a transcontinental railroad with a route through the territory.

He wanted it organized as a first step to statehood.

He wanted to prevent Mexico from annexing the territory.

Stephen Douglas wanted the Kansas-Nebraska Territory organized because he wanted a transcontinental railroad with a route through the territory. This movement would very much benefit Douglas' Illinois constituents as well as for him to maintain civic-control towards such territory. Southern senators objected such proposal, hence the area was deemed as a free-state.