"The private equity-backed firm is seeking to cut nearly $6bn in debt after years of disappointing passenger numbers. Brightline was seen as a test to whether private companies could run intercity railway lines in America, where public-transit systems are sparse. It operated the first privately owned rail service in the country, linking Miami and Orlando." - The Economist
I'm not sure if that last statement is true. I think there were many private rail passenger services back in the day.