I wouldn’t think that it would be legislation. My guess is that the railroad petitioned the ICC for abandonment, showing the lack of online customers on the segment to be abandoned. They would then have to document alternative routes for both freight and passenger customers, such as via Danbury or via Devon. Based on that testimony, and basing it against the objections, such as if XYZ Coal Company got 30 cars per year. The railroad would have to show how the 30 cars over a year was running at a loss based on maintenance, equipment utilization, crew wages… In the end the ICC ruled that the abandonment should go through. I’m sure that somewhere on line are ICC rulings. If not, the National Archives would be where documents pertaining to this transaction would be found.