The drivers made no stops and dropped all the passengers off at the end of the line, her granddaughter, Claire Hartfield, remembers her saying years later.
"She was new to the city," Hartfield recalls. "She wasn't really aware of the tensions that had been building. She was just enjoying some of the excitement of being in a really big city.
"It was an ... eye-opener for her."
But other passengers on the next routes weren't lucky enough to escape.
"Street-car routes, especially transfer points, were thronged with white people of all ages," a 1922 report by the Chicago Commission on Race Relations
says. Black passengers were dragged out to the street, beaten and kicked.
Over the next few days, white mobs stormed the streets attacking blacks indiscriminately. Thirty-eight people were killed, 23 of whom were black, and more than 500 were injured, the commission on race relations said.
Chicago wasn't the only city besieged by mob violence in the months after World War I. White gangs were eager to maintain Jim Crow-era laws but African-American soldiers returning from the war were demanding their rights and an end to second-class citizenship. Between late 1918 and late 1919, the US saw 10 major anti-black riots, dozens of minor, racially charged clashes and almost 100 lynchings, writes David F. Krugler, author of "1919, The Year of Racial Violence: How African Americans Fought Back."
Scores of black men and women were killed that year in racial violence. Nobody knows how many. The official death toll, Krugler says, was more than 150 people -- the majority of whom were black -- across the country between late 1918 and 1919. The Arkansas State Archives says 200 blacks were killed in Arkansas alone over several days in September 1919.
"Overwhelmingly, it was whites attacking blacks," Krugler told CNN.
But for nearly 100 years, the "Red Summer" as it was called by NAACP field secretary James Weldon Johnson because of its explosive violence and bloodshed, went overlooked and forgotten.
"The Red Summer doesn't fit into the stories we tell ourselves about US history," Krugler says. "It's also a very prominent example of another feature of American history that we don't like to fully acknowledge."
Until today, very little has been recorded about the violence that occurred.
"When I wrote my book, people wouldn't talk about it," Cameron McWhirter, author of "Red Summer: The Summer of 1919 and the Awakening of Black America," told CNN. "People have spent a lot of time not focusing on it. (There's) a lot of focus now on trying to uncover this part of history."
A panicky time for white America
"A lot of people would think that 1919 was this heroic happy time for America because we just won the war," McWhirter says. "But this wasn't the case. It was a panicky time for America."
There were strikes across the country, rising prices and unemployment, returning veterans who couldn't find a job and the spread of Communism.
"In the midst of all that, we have America's racial problem," he says.
While hundreds of thousands of soldiers had been fighting across the ocean, some 5 million African Americans -- including Shepherd -- had migrated from the South to cities like Chicago, where factory owners welcomed the cheaper labor and where, according to McWhirter, the newcomers were being treated "slightly better."