Higgins was the co-founder and treasurer of the Anti-Vaccination League of America. The League was created in 1908 by Higgins and industrialist
John Pitcairn. Its anti-vaccination campaigns focused on
New York and
Pennsylvania. Higgins was the League's chief spokesman and pamphleteer. Historian
James Colgrove noted that Higgins "attempted to overturn the New York State's law mandating vaccination of students in public schools." The League dissolved after the death of Higgins in 1929. ==Selected publications==