After the incident aboard the streetcar, Jennings took her story to this extended family. Her letter detailing the incident was read in church the next day; supporters forwarded the letter to The New York Daily Tribune, whose editor was the abolitionist Horace Greeley, and to Frederick Douglass' Paper, which both reprinted it in full. Meanwhile, her father made contact with a young white lawyer named Chester Arthur.

Arthur, who would go on to become president upon the assassination of James Garfield in 1881, was at the time a beginner in his 20's only recently admitted to the bar. He nevertheless won the case, against the Third Avenue Railway Company; a judge ruled that "colored persons if sober, well behaved, and free from disease" could not be excluded from public conveyances "by any rules of the Company, nor by force or violence," according to newspaper reports. "Our readers will rejoice with us" in the "righteous verdict," remarked Frederick Douglass' Paper.

NEW YORK before the Civil War resembled the Jim Crow South of Rosa Parks's era in at least this respect: A pervasive racial caste system decreed that a great deal of space -- in schools, restaurants, workplaces and churches -- was strictly off-limits to African-Americans. The city's transit system, in its infancy, was a particularly bitter proving ground.

In the 1830's, when the first omnibus routes were established, the newspaper The Colored American told black New Yorkers, "Brethren, you are MEN -- if you have not horses and vehicles of your own to travel with, stay at home, or travel on foot" rather than be "degraded and insulted" on city coaches. But by the time Elizabeth Jennings boarded the streetcar at Chatham and Pearl Streets, the avenues churned with horse-powered public transportation, and the city stretched far beyond 42nd Street, a long way to walk.

Jennings's legal victory did not complete integration of city transit. But blacks actively tested her precedent, in part through the Legal Rights Association, which her father founded for that purpose. In 1859, another case brought by that group resulted in a settlement, and by the following year nearly all the city's streetcar lines were open to African-Americans.

And Elizabeth Jennings? The details of her life have been told most painstakingly by John H. Hewitt, who, in his 1990 study in the journal New York History, reported that he had not uncovered a single biography of the woman, "not even a thumbnail sketch."

But a few things he did learn. She kept teaching. She married a man named Charles Graham. During the 1863 draft riots, when largely Irish rioters vented their rage at a new conscription law on the black people who were their most direct competitors for jobs and homes, Elizabeth and her husband were likely at home on Broome Street, bent over their ailing year-old son, Thomas. According to his death certificate, the child died of "convulsions," perhaps a last manifestation of one of the infectious diseases that sent urban death rates soaring in those years. While the city was reeling in the aftermath of its worst street melee yet, the couple were laying their son's small body to rest in Cypress Hills Cemetery in Brooklyn.