For the record,

Plessy Vs. Ferguson involved a railroad that operated a mixed race coach
into the South (I forget what state.)

They were sued, and the Supremes ruled that the railroad had to comply
with state law...that is provide seperate coaches (at their expense) for
"whites" and "coloreds".

As a business, the railroad would have preferred the cheaper, one car
solution, but were forced, BY LAW to provide segregated facilities. That
the facilities were supposed to be of equal quality is the only part
that anyone remembers.

Best Regards,

DAve