But as they turn the corner on their way to a rally at St Thomas Aquinas church in a rundown area of South Philadelphia, they break out into a lingua franca of freedom songs and rousing chants. Waving banners, they make their way through a tunnel of applause from residents, religious leaders, trade unionists and civil rights activists as two black women hand them yellow carnations.
But for these passengers the destination is not as important as the journey itself.
The Freedom Riders are a caravan of 18 buses from 10 cities stopping in 103 cities to campaign for greater rights for immigrant workers. They are converging on Washington DC, and then will finish their journey at a rally tomorrow in New York. High on their list of demands are legalising the status of undocumented immigrants, family visas and improved employment protection.
Based on the original Freedom Ride of 1961, when a racially mixed group of civil rights campaigners travelled through the southern states to challenge segregation, each bus stops to speak to workers and attend rallies in immigrant areas.
If the route of this bus is circuitous, the manner in which many of its passengers made it to the US has been no less so.
Lorenzo Aldana left Guatemala where he was foreman on a building site in 1986. His father sold part of his farm to pay $1,000 to a trafficker who left him stranded in Mexico.
Mr Aldana worked in the town of Mexicale for a year to save money to complete the journey.
"I didn't want to go back to Guatemala," he says. "I am the oldest son and I had to get to America to support my family."
He trekked eight hours overnight with 30 others, including three women and six children and made it to California where he got a job picking fruit. Working long hours for less than the minimum wage, he was unable to protest for fear that he would be reported to the authorities.
Seventeen years later he pays taxes but still cannot vote.
"I'm here because I want those people in California to know that they are not alone," he says through an interpreter.
"I want legalisation so that I can have a better life."
Illegal immigrants in the US often pay taxes and live freely for years. But clampdowns since September 11 2001 have made leading a quiet life more difficult.
With around 8 million illegal immigrants in the country the American workforce - particularly in agriculture, hotels and cleaning - depends on people such as Mr Aldana almost as much as his family depend on him.
"America is either dependent on, or flourishes because of, illegal immigrant workers," says Dan Clawson, a sociology professor and author of The Next Upsurge, Labor and the New Social Movements.
"The country could still function without them but it would function very differently because so much hinges on an economy run on low wages and no benefits."
While the nationalities and journeys of the protagonists may differ, the themes they bring with them are similar. They have travelled thousands of miles from some of the poorest places to the richest country in the world. But they still remain on the margins, even if in the US they are geographically closer to wealth.
Each one has a tale of economic migration that has separated families, many have swapped skilled low-paid professional work in the developing world for unskilled and relatively higher-paid menial jobs in America.
Luz Medina went from being an elementary school teacher in Colombia to a janitor and cook in Boston so she could send money to her sick mother and two daughters at home.
Ana Amaral from Angola says she lost her job as an international telephone operator in Brazil after an American company bought the firm and fired 5,000 people. She became a cleaner in the US to support her mother and children in Brazil.
"It's globalisation," she says. "The Americans came to my country and so now I am here."
Some people on the bus, like Ms Amaral, Ms Medina and Mr Aldana, are illegal immigrants. Others, like Nazda Alam from Bangladesh, or Melvin from Barbados, are legal. "Someone paved the way for me so I will need to pave the way for someone else," Melvin says.
And some are Americans keen to show solidarity.
"Standing up for other people's dignity and civil rights is the same as standing up for your own," says Elmer Stanley, who was raised in Virginia during the civil rights era.
Illegal immigrants taking part in the protest are taking the greatest risk. All protesters wear a tag around their necks saying they are taking part in a peaceful protest, and wish to remain silent. It offers the number of a lawyer. Just outside El Paso in Texas two buses were stopped by US border patrol agents at a checkpoint, even though they had not left the country.
The original Freedom Riders of the 1960s were met with violent hostility from segregationists in Alabama who beat them with metal bars and firebombed their buses. Freedom Riders today have also encountered opposition to their campaign.
In some cities a handful of anti-immigration protesters have turned up. A group called "Stop the Invasion" met them in Durham, North Carolina, to demand the deportation of the undocumented riders.
"What they are really demanding is a free ride," says David Ray from the Federation for American Immigration Reform. "Free from respecting our immigration laws and free from the obligations to respect fair and legal immigration."
But when they rolled in to the small town of Reading, Pennsylvania, and Philadelphia, the only tattooed white men there were trade unionists to support them.
"The exploitation of undocumented workers drags down the general standard of living of all workers," says Bill Heenan, the business manager of the Local 471 union that represents workers in three counties. "But that's not their fault. My mother's family was from Ireland and worked in the garment industry and my father's family was from Lithuania and worked in the coal mines and even though they were legal they went through a similar thing."
Confronted with the question of why she doesn't go home if she doesn't like it, Ms Amaral smiles. "First of all I can't go back because people are dependent on me for money. But secondly why should I?" she asks, gesturing to the people on the bus. "We made this place."