b. October 2, 1811, in Paris, Kentucky; d. July 22, 1885, in Atlantic City, New Jersey. Dickey attended Ohio University in Athens and graduated from Miami University at Oxford, Ohio, in 1831. He taught school in Ohio and Kentucky before moving to Macomb, Illinois, in 1834. He studied law and gained admission to the bar in 1835. In 1836, he moved to Rushville, Illinois, where he edited a Whig newspaper, speculated in real estate, and continued the practice of law. During the Economic Panic of 1837, Dickey lost all of his money, and he moved to Ottawa, Illinois, in 1839 in order to regain his fortune. With the outbreak of the Mexican War, Dickey raised a company of volunteers and served in the war as a commissioned captain. Dickey returned to Ottawa, and in 1848, he was elected judge of the Ninth Judicial Circuit. He occasionally served as the judge on the Eighth Judicial Circuit in the absence of Judge David Davis, and in that capacity ruled on numerous cases argued by Abraham LIncoln. He resigned from the bench in 1853 but continued to practice law in Ottawa.

Dickey later opened a second law office in Chicago, Illinois. He was a delegate to the first Republican state convention of 1856, but he supported Douglas over Lincoln in both the 1858 senatorial and 1860 Presidential campaign and spoke throughout the state on Douglas's behalf. During the Civil War, Dickey served as a colonel of the Fourth Illinois Cavalry, and later, as a member of General Ulysses S. Grant's staff. As Assistant Attorney General of the United States, from 1868 to 1870, he was responsible for all suits in the court of claims and frequently appeared in the United States Supreme Court. In December of 1875, he became a justice of the Illinois Supreme Court and held that position until his death.