Born September 1, 1822 in Russellville, Kentucky, Ewing attended the public schools. He completed preparatory studies. He was graduated from Centre College, Danville, Kentucky, in 1840 and from the law school of Transylvania University, Lexington, Kentucky, in 1843. He studied theology at the Baptist Seminary at Newton, Massachusetts, in 1845 and 1846. He returned to Kentucky and practiced law in Russellville. He served as member of the Kentucky House of Representatives in 1848 and 1849.
Ewing was elected as a Whig to the Thirty-second and Thirty-third Congresses and served from March 4, 1851, until his death in the town of Mammoth Cave, Kentucky, September 27, 1854. He was interred in Maple Grove Cemetery, Russellville, Kentucky.