What caused the demise of state-based railroad regulation? how was the demise related to the passage of the interstate commerce act?

The demise was created by the fact that there was no federal legislature about them. What happened was that large companies that owned railroads worked together on creating cartels and monopolies and trusts and they increased prices for railroad usage. The people were sick of this and yet they had to use the railroads, so eventually the Act was created to stop this.