Adams served in several local offices in Quincy, including town meeting moderator, school board chairman and judge of the local court. He was elected to the Massachusetts state legislature as a Republican, but soon switched to the Democratic Party because of his dissatisfaction with Republican Reconstruction policies. In addition to serving in the Massachusetts House of Representatives in 1865, 1867, 1870 and 1873, he was the unsuccessful Democratic nominee for Governor of Massachusetts in every year from 1867 to 1871. (Governors served one year terms until 1918.)