 He was the prosecuting attorney of Richmond from 1842 to 1846 and judge of the Richmond and Henrico circuits from 1846 to 1849.Caskie was elected a Democrat to the United States House of Representatives in 1850, serving from 1851 to 1859.After being unsuccessful for reelection in 1858, he resumed practicing law until his death in Richmond, Virginia on December 16, 1869.