 She married diplomat Robert Liston on 27 February 1796 and the couple arrived in the United States in 1796.While in the US, Henrietta Liston visited 16 states, collected botanical specimens and established friendship with George Washington and John Adams, of whom her diaries contain favourable impressions.She and her husband are credited with preparing an early foundation for the long-term "Special Relationship" between the United States and United Kingdom.