This article traces the making of “unaccompanied alien minors (UAMs)” as an inadmissible class at the US border. This category which first appeared in the Immigration Act of 1907 was a milestone in the codification of what I call the guardianship principle: foreign-born children needed the support of their father or guardians legally responsible and socio-economically capable for their protection in the United States.

As more Americans felt concerned about padrones, the US government made the first step in creating the guardianship principle, with the passage of the Padrone Act of 1874. Over time, immigration officials examined more closely the background of children arriving without parental supervision. In 1887, the Treasury Department issued an order to exclude “children unaccompanied by families or friends and presumed to be from charitable institutions.” Still there was no law to prohibit their entry for arriving alone and unsupported.

William Williams, whom President Theodore Roosevelt assigned to Ellis Island in 1902, played a key role in the categorization of unaccompanied alien minors as an inadmissible class. By the turn of the century, the growth of the crusade against child labor made it easier for the immigration service to exclude solitary children on the ground that they would need parental protection abroad. On June 20, 1903, Commissioner Williams posted a notice that would henceforth prevent the release of unaccompanied children without extra scrutiny. Under his command, frontline inspectors demanded more identifying information from each arriving child. This procedure, on the one hand, allowed immigration officials to deliver more children to their rightful guardians in the United States. These officials contacted their alleged family members, asking parents to come and pick up their loved ones from the immigration station. Many youngsters were now relieved from the challenge of finding out where their parents were and how to get there. On the other hand, the same procedure revealed that not all child migrants were able to establish who they were and with whom they were to live in the country. Williams urged the exclusion of such children by claiming that their entry might result in unwanted outcomes, such as an increase in child labor in the United States. As more states enacted state laws regulating child labor, immigration officials had more reasons to deny their ability to be self-supporting in the country and dismiss their allegations.

As US immigration authorities started excluding children arriving unaccompanied, Greek boys emerged as targets of profiling at the US border. Statistical records suggest that the number of Greek entrants under age fourteen declined after Williams prohibited frontline inspectors from admitting unaccompanied minors without reporting them to his office. Around the time when the Immigration Act of 1907 came into force, American reformers believed that Greek boys as most frequent victims of child trafficking. Hence, they had no substantial reason to oppose the preventive exclusion of child migrants to suppress the padrone system.