James Campbell was born in 1812 in Southwark (now part of Philadelphia), Pennsylvania. He studied the law, was admitted to the state bar in 1833, and began work as a lawyer. Campbell soon entered local politics and served on the city board in 1840. One year later, the governor appointed Campbell to a seat in the Philadelphia Court of Common Pleas.

A Democrat and a Catholic, Campbell had to contend with anti-Catholic sentiment, a factor which contributed to his 1850 electoral defeat as judge to the state supreme court. Campbell secured a political position that year when he was tapped by the new Democratic governor, William Bigler, to serve as state attorney general. When Franklin Pierce was elected President in 1852, he nominated Campbell as his postmaster general, a position Campbell held for the entirety of the Pierce administration (1853-1857).In 1860, Campbell was a driving force behind the organization of a unity party that nominated former secretary of the treasury James Guthrie for President and New York governor Horatio Seymour for vice president. This ticket failed to prevent Abraham Lincoln’s election as President of the United States, and Campbell failed himself in his bid for the United States Senate in 1863. James Campbell practiced law until his death in 1893.