Charles J. Biddle graduated from Princeton in 1837, where he studied law, and was admitted to the bar in 1840. He served in the Mexican War, where he was promoted to the rank of major. At the close of the war, he returned to Philadelphia to practice law.
In 1861 he was appointed a colonel in the Pennsylvania reserve volunteer corps, and in October of that year was elected to Congress, to fill the vacancy caused by the resignation of Edward J. Morris. He was tendered a commission as Brigadier-General, but declined it.
After the American Civil War he became one of the proprietors and editor-in-chief of the Philadelphia Age, and retained that place during the remainder of his life. His literary work was confined mainly to editorial contributions to the columns of this journal. His only separate publication is The Case of Major Andre, a carefully prepared essay read before the Pennsylvania historical society, vindicating the action of George Washington. The immediate occasion was a passage in Lord Mahon's History of England, which denounced the execution of Andre as the greatest blot upon Washington's record. By an authority so high as the London Critic, this essay was subsequently pronounced a fair refutation of Lord Mahon's charge.