James Cochrane Dobbin was born in 1814 in Fayetteville, North Carolina. He graduated from the University of North Carolina in 1832, was admitted to the state bar in 1835, and established his law practice in Fayetteville in 1835.

Dobbin served in the U.S. Congress as a Democrat from 1845 to 1847 but declined to run for reelection, choosing instead to return to his law practice. He did not remain out of politics for long, however, for in 1848 he began the first of three two-year terms in the state House of Commons, rising to become its Speaker (1850-1852).Dobbin then served as a delegate to the 1852 Democratic National Convention; one year later, he was named by President Franklin Pierce as secretary of the Navy, a post he held from March 1853 to March 1857.

After leaving his cabinet post, James Cochrane Dobbin succumbed to tuberculosis and died in August 1857.