The 1905 citizenship court case against S. Hollister Jackson arose as an attempt to disqualify him from serving as State's Attorney for
Washington County, Vermont. Brought by Charles A. Phelps, whom Jackson was prosecuting for crimes, the case alleged that Jackson, born in Canada, was not a U.S. citizen and thus unqualified to hold office. This legal maneuver was intended to derail Jackson's prosecution efforts by challenging his eligibility based on citizenship. The petition claimed that Jackson's father, Rev. Samuel N. Jackson, and grandfather, Horatio Nelson Jackson, had forfeited their U.S. citizenship through extended residence and duties in Canada. They argued that Jackson was born to alien parentage and had never been naturalized. In his defense, Jackson presented evidence showing that his father had always considered himself an American, returned to the U.S. before Hollister turned 21, and took the
Freeman's Oath. Witnesses testified that Jackson met all legal requirements for citizenship and public office in Vermont. The Vermont Supreme Court heard the case in early 1906, with both sides presenting extensive arguments on naturalization laws and citizenship by descent. Ultimately, the court ruled in Jackson's favor, allowing him to retain his office. ==Election as lieutenant governor==