He attended the common schools, studied law, and was admitted to the bar in 1836 commencing practice in Elizabethtown, Kentucky.
Jewett served as the prosecuting attorney of Hardin County, Kentucky. He was elected as a Democrat to the Thirty-fourth and Thirty-fifth Congresses (March 4, 1855 – March 3, 1859). While in Congress, he served as chairman, Committee on Expenditures in the Department of War (Thirty-fourth Congress), and as chairman, Committee on Invalid Pensions (Thirty-fifth Congress).
He was an unsuccessful candidate for reelection in 1858 to the Thirty-sixth Congress.
After leaving Congress, he resumed the practice of law. He died in Elizabethtown, Kentucky in 1861 and was buried in the City Cemetery.
Member United States House