Peleg Sprague earned an Artium Baccalaureus degree from Harvard University and subsequently read law. He began his legal career in Augusta and Hallowell, District of Maine, before transitioning to public service as a member of the Maine House of Representatives. Sprague later served in the United States House of Representatives and Senate, showcasing his legislative expertise. After a stint in private practice in Boston, he was appointed as a United States District Judge for the District of Massachusetts, demonstrating a blend of legal and judicial acumen.

Peleg Sprague's political identity is marked by a staunch opposition to the Indian removal policy, framing it as both corrupt and inhumane. His vocal resistance against President Andrew Jackson’s approach reveals a deeply principled stance that prioritizes moral integrity over political expedience. Sprague's legislative actions and public rhetoric highlight an unexpected alignment with humanitarian concerns, challenging the prevailing political winds of his era. This ideological agility and principled opposition compel one to consider how Sprague reconciles such a stance with the broader political landscape of his time.