Nathaniel Baker graduated from Phillips Exeter Academy and Harvard College, studying law under prominent figures before being admitted to the bar in 1842. He began his career in public service as a clerk and county clerk, later becoming Chief Fire Engineer for Concord's Fire Department. Baker served in the New Hampshire House of Representatives, including a term as Speaker, and held various military roles in the New Hampshire Militia. He was elected Governor of New Hampshire, though he was not reelected. Transitioning to Iowa, Baker practiced law, joined the Republican Party due to his antislavery views, and served in the Iowa House of Representatives, where he chaired the Military Affairs Committee during the Civil War. He played a significant role in recruiting, equipping, and training soldiers, and was noted for his efforts in preserving Confederate memorabilia.

Nathaniel Baker's political identity is marked by an unexpected blend of fiscal conservatism and progressive civil rights advocacy. His tenure as governor saw a focus on state financial prudence, yet he switched from Democrat to Republican due to his staunch antislavery views. Baker's military service during the Civil War showcased his commitment to meticulous record-keeping and soldier welfare, while his post-war efforts in collecting Confederate memorabilia reveal a nuanced approach to historical preservation.