The main push behind the discussions about building a trans continental railroad in the mid-1900s was

The main push behind it was aimed at how to connect the pacific coast with the remaining part of the nation.

Explanation:

The transcontinental railroad is a railroad network that connects the continental landmass with the terminals at different continental borders.

The transcontinental rail road project aided in the opening of up of settlements that are in the under populated region and that wouldn't have been known or explored. The transcontinental railroad helped cross country passengers and also freight transportation.

answer; /// i believe that the correct answer is (d)the huang he river valley;

the section of the chart that represents a point at which a bill needs approval from a majority of people in both chambers to advance is j, as this is the only section before the bill becomes law which has both rows (symbolizing the chambers) converging into one, meaning that the two parts of the congress have to approve of it before it can march on with the process.