What was a result of rail standardization

Railroad gauge went to a standardization because the built rails soon met. A standard rail will make it easier for trains to go across from one rail to another. Engineers before used different gauges which would not fit be correctly fit and would be difficult if the rails were all different. 
It was a costly project but was a necessary move for easier and fast transportation. 

Primary sources are usually  more accurate and are written by someone who experienced it or witnessed it. secondary sources are those who heard of it after the fact that can lose details and or twist the event in a light that benefits them.