Why did the government choose a northern route for the transcontinental railroad?

The transcontinental railroad was commissioned during the American Civil War, when only Northern delegates sat in the Union Congress. Without Southerners to argue for the railroad in their region, the project went to the North.

#2 there were also so considerable geo-economic concerns. the northern route was rich in natural resourses such as coal and water (both extreemly important to the rr industry). it was also more highly agricultural and industrial, thus assuring greater economic trade. also, the timber, fur, mineral and real estate opportunities were much greater in the north