Born in Fayette, Missouri in 1854, Shafroth graduated from the University of Missouri in 1875. Shortly after his graduation, having privately studied the law, Shafroth was admitted to the Missouri Bar and in 1879 he moved to Denver to establish a legal practice. By 1881, he had married and become in partner in the firm of Stallcup and Luthe. In 1882, Shafroth's partner, H. E. Luthe, had become a prosecuting attorney for the Second Judicial District of Colorado, and had made Shafroth his assistant. In 1889 Shafroth was elected to the office of Denver District Attorney, and in 1894 he was elected to the U.S. House as a representative of Colorado. As a representative, Shafroth championed such issues as women's suffrage and improving public roads. The silver panic of 1893 led Shafroth to become a leading member of what became known as "Silver Republicans", who advocated the free and unlimited coinage of silver. In 1902, after two successful reelection campaigns, Shafroth became embroiled in a voter fraud scandal; subsequent investigation by his own office confirmed the accusations to be true, and Shafroth resigned his office and returned to Denver. This display of integrity led to the origin of the nickname of "Honest John." Shafroth ran for office again in 1904 but lost. By 1908, he was elected Governor of Colorado, and for two terms he waged a campaign against political corruption in both parties within Colorado. His success on this front led to his election as a U.S. Senator in 1912. Shafroth played a prominent role in the creation of the Federal Reserve Act in 1913, as well as a number of other measures related to public land laws. In 1918 he lost his senate seat to Lawrence C. Phipps, and Shafroth spent the remainder of his life in private law practice. He died in Denver in 1922.