Campaigners in favour of tightening US immigration laws have set off on a 12-city tour to try to build support for their cause.
Minuteman Project members have staged protests in recent weeks
The Minuteman Project, which patrols the US-Mexico border, launched the 10-day convoy following pro-immigrant mass rallies across the country.
They hope to pick up support as they travel from Los Angeles to the capital.
It comes as the US Senate prepares to try again to break the deadlock on immigration reform.
The Minuteman group is made up of volunteers who strongly oppose illegal immigration, and organise border patrols to try to prevent people crossing into the US illegally.
MINUTEMAN CARAVAN TIMETABLE
3 May: Los Angeles, CA
3 May: Phoenix, AZ
4 May: Albuquerque, NM
5 May: Abilene, TX
6 May: Crawford, TX
7 May: Little Rock, AR
8 May: Memphis, TN
8 May: Nashville, TN
9 May: Birmingham, AL
9 May: Atlanta, GA
10 May: Greensboro, NC
11 May: Richmond, VA
12 May: Washington DC
It says it will use the caravan to mobilise voters and recruit members, and try to counter the impact made by the huge pro-immigrant rallies held earlier this week.
The caravan left Los Angeles on Wednesday, where it highlighted unemployment in the African-American community.
It said the problem was caused by illegal immigrants taking jobs "that Americans would be willing to do".
But some black activists accused the Minuteman group of racism.
"The Minutemen are a racist hate group. They are just using us to support their cause," Najee Ali was quoted as saying by Reuters news agency.
The group is planning to hold rallies in cities including Phoenix in Arizona, and Crawford in Texas, where President George W Bush has a ranch.
The convoy will finish by driving to Capitol Hill in Washington DC for a rally on 12 May.
US ILLEGAL IMMIGRANTS
About 11.5m illegal immigrants in the US
Four out of 10 have been in US five years or less
75% were born in Latin America
Most enter via southern US border
California, Texas and Florida host most illegal immigrants
Many work in agriculture, transport and construction
"Our power is not putting a million people on the street, our power is putting 10 million people at the voting box," said executive director Stephen Eichler.
The US Senate's majority leader, Bill Frist, said on Tuesday the Senate would try again within weeks to break the deadlock on immigration reform.
He was speaking after huge demonstrations on Monday illustrated immigrants' demands for recognition.
Congress is caught between competing bills that would either criminalise or legitimise illegal immigrants.
Mr Frist said his attempts at reconciliation would focus on "border security first and foremost".
But he acknowledged that legislation also had to address the issue of the estimated 11.5 million illegal immigrants in the US.