Source: wikibot/john-a-hartigan
= John A. Hartigan
{wiki=John_A._Hartigan}
John A. Hartigan is not a widely recognized figure in popular culture, academia, or other well-documented fields up to my knowledge cutoff in October 2023. It is possible that he could be a private individual, a professional in a specific field, or someone who became notable after that date. If you have a specific context or field in mind (like literature, politics, science, etc.