The Pastors for Peace (PFP) organisation made their fifteenth trip to the Communist state on Saturday, travelling there via Mexico.
Despite the threat of $7500 fines for each of 120 expedition members, the humanitarian convoy arrived in Havana with school buses, medicines, medical equipment, computers and books.
Many arrived in Cuba's capital wearing T-shirts that said "Regime change in the US, not in Cuba".
PFP is an arm of the Interreligious Foundation for Community Organisation, an ecumenical group based in Harlem, New York.
Since 1992, it has delivered 2350 tonnes of aid to Cuba without requesting a US government license, Cuban officials said.
PFP promised that their work for "a more humane and reasoned US policy toward Cuba" would continue.
The group wants to see an end to what they describe as "the immoral US economic blockade" that began in the early 60s.
Group leader Lucius Walker told Aljazeera.net on Saturday that this year's mission comes at a crucial time for some of the "most disadvantaged people in the world".
He also condemned US President George Bush's administration "provocations and aggressions against Cuba" and cited the new policies prepared by the US Presidential Commission for Assistance to a Free Cuba.
He said these policies include plans to fly a C-130 military cargo plane constantly around Cuban waters, in order to beam in US government propaganda on TV/Radio Mart?.
A million Cubans protested US
blockade policy in May 2004
Other ideas include plans to spend millions of American tax payers' dollars on appropriations to fund an internal opposition movement in Cuba
But PFP's head was most damning of the increased restrictions on travel.
"Even Cuban-Americans would be allowed to visit Cuba only once every 3 years, only to visit their most immediate relatives, and only if they apply for a US Treasury license."
Will for change?
Walker believes a growing number of Americans want to reverse hostile US policies toward Cuba that date from Castro's 1959 revolution in the midst of the Cold War.
He pointed to Republican congressmen who voted on Wednesday to overturn a White House decision to bar people in the US from sending parcels with food, soap and other personal hygiene products to Cuba.
The convoy was received by government official Caridad Diego. She expressed Havana's appreciation for the generosity of ordinary US citizens despite the White House's "spiteful determination" to do Cuba harm.
The president of the Cuban Institute for Friendship, Sergio Corrieri, added that the equipment and medical supplies would be put to good use and would benefit hundreds of people.