He was born in East Bridgewater in the Province of Massachusetts Bay on March 9, 1776.

Whitman was a delegate to the convention in 1819 that framed the first State constitution of Maine.

He was elected to the Seventeenth Congress from Maine and served from March 4, 1821, to June 1, 1822, when he resigned.

Whitman served as chief justice of the Maine Supreme Judicial Court 1841-1848.

He retired in 1852 and returned to East Bridgewater, Massachusetts, where he died on August 1, 1866.