The lawsuit framed the removal as an unlawful interference with a common carrier’s legal obligation to serve the public. Common carrier doctrine — the body of law governing companies that offered transportation or other services to the general public — held that such carriers could not refuse passengers without lawful cause. The argument Arthur would make was that Elizabeth Jennings’s race was not a lawful cause for refusal, and that the company’s agents had exposed it to liability by physically removing her.
This was not a simple or obvious legal argument in 1854. The legal status of Black Americans’ rights as passengers on common carriers had not been cleanly resolved. What the case required was a jury that would accept the argument and a judge whose instructions would give that argument legal weight.
## The Trial: February 22, 1855
The trial was held on February 22, 1855 — a date that happened to be Washington’s Birthday, though sources do not indicate that was deliberately chosen. It proceeded before Judge William Rockwell with an all-white male jury.
Judge Rockwell’s instructions to the jury became the pivotal element of the case. In charging the jury — the moment when a judge explains the law the jury is to apply to the facts they’ve heard — Rockwell told them several things that together constituted a significant statement of principle.
He instructed the jury that the railroad company was liable for the acts of its agents, whether those acts were careless or willful. He instructed them that as common carriers, transit companies were required to carry all “respectable” persons. And he instructed them that “colored persons, if sober, well-behaved, and free from disease,” had the same rights as others to ride in streetcars and could not be excluded “by company rules, force, or violence.”