Nathaniel Peabody was born in 1741 in Topsfield, Massachusetts, and later moved to Plaistow, New Hampshire, where he began practicing medicine. He transitioned his practice to Exeter, New Hampshire, and became actively involved in revolutionary activities, including the raid on Fort William and Mary. Peabody held various leadership roles in the New Hampshire militia and was elected to the revolutionary assembly and the Committee of Safety. He served in the Continental Congress and played a pivotal role in drafting the New Hampshire state constitution. Peabody also represented Rockingham County in the State Senate and ran unsuccessfully for multiple state and national offices throughout his career.

Nathaniel Peabody's political identity is marked by a steadfast commitment to revolutionary principles, combined with a pragmatic approach to governance. He consistently advocated for state-supported initiatives in education and medicine, revealing an ideological alignment with progressive social investments. Peabody's military career, highlighted by his participation in pivotal revolutionary actions and his principled resignation from the militia, underscores a dedication to anti-imperialist sentiments. His legislative endeavors, particularly in drafting the New Hampshire state constitution, showcase a calculated effort to balance regional interests with broader revolutionary goals.