Abdirizak Mohamed Warsame, 20, made his initial appearance in federal court on charges of conspiracy to provide material support to a foreign terrorist organisation.
Court documents allege Warsame, who was arrested yesterday night, tried to help other young men from Minnesota's Somali community travel to Syria to fight for the Islamic State group.
Nine others in that group have already been charged, authorities say.
Warsame gave a slight wave to family and friends gathered for his initial appearance.
His relatives declined to comment as they left the courthouse.
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Warsame was deemed qualified for a federal defender after telling the judge he had no assets and his only income was a USD 14-an-hour job at a private security company, Securitas.
Chief federal defender Katherian Roe represented Warsame at the hearing but said he would be assigned another lawyer going forward.
Roe told the judge that he had testified before a federal grand jury, but she didn't give details.
Another hearing was set for Tuesday.
Court documents allege Warsame and others settled on a plan of going to Syria by way of Mexico.
According to an FBI agent's affidavit, one man who was planning to leave for Syria appointed Warsame to replace him as "emir," or leader, of the group.
"As the new emir, Warsame immediately encouraged those with passports and money to travel to Syria by the end of the upcoming summer," the affidavit said.
The document says Warsame gave another man USD 200 for an expedited passport application. Warsame also applied for a US passport on an expedited basis but was denied.
One man made reservations for a May 2014 flight from Minneapolis to Istanbul, Turkey, with the intention of going on to Syria, the document said.
The day before the man was to leave, Warsame accompanied the man and two others to a public library where the man printed out his itinerary.