Born in Russell County, Alabama in 1848, Grant grew up in the Old South and served briefly in a Confederate regiment during the final months of the Civil War. With the southern economy in ruins, he set out for Davenport, Iowa and persuaded a well-to-do uncle, also named James Grant, to finance his education. Grant attended Iowa State and Cornell Universities, then the Bergakadmie in Freiberg, Saxony, studying metallurgy and mining.
Following his education, Grant began working as a mining engineer in Central City, but it was in the carbonate camp of Leadville that he would make his fortune and reputation. Examining ore in the region for the Pueblo & Oro Railroad in 1877, Grant visualized the profitability of building a smelter. In 1879, Grant enlisted financial backing from that same uncle, and formed a partnership with Edward Eddy and William James to construct the Omaha and Grant Smelter in Leadville. Processing ore from local mines like Horace Tabor's Little Pittsburgh, the smelter shipped $2,400,000 worth of metals the first year, contributing to Leadville's mining boom and influencing railroads to build to the camp. Grant was well regarded in Leadville, paying investors, suppliers, mining and coking firms promptly. On the night of May 24, 1882, a fire engulfed the Leadville smelter and it burned to the ground. Even as Grant and his associates scrambled to process ore already purchased, they decided to rebuild the plant north of Denver, east of the Platte River and near existing railroad lines. While the smelter was under construction, ore and fuel was shipped from the mountains, ready to be processed as reduction units were completed. The Omaha and Grant Smelter was fully operational by November, just as Grant assumed the office of Governor. Like other politicians in the Gilded Age, Grant was able to devote time to both his role as governor, improving conditions for Colorado's commerce and mining industries, and to the profitable smelting business.
Grant's success in the smelting business brought him considerable wealth, and in 1902, he built a mansion at 770 Pennsylvania Street in Denver. The following year, strikes by the Mill and Smeltermen's Union, outdated methods of reduction and a scarcity of rich ores led to the closure of the smelter. When Grant passed away in November, 1911, his wife remained in their big mansion for six years before selling it to oilman Albert E. Humphreys in 1917. Today, the smelter site is occupied by the Denver Coliseum and the Grant Humphreys Mansion is owned by Historic Denver.
Thirty-four year old James B. Grant, third Governor of Colorado, in 1882