Carbon is a city in Douglas Township, Adams County, Iowa, United States. The population was 36 at the 2020 census. Note that other places in Iowa have been named Carbon: there was a Carbon Post Office in Davis County, six miles south of Ottumwa, that operated for less than a year in 1881. There was also a Carbon Post Office in Webster County, three miles south-east of Fort Dodge, that operated from 1870 to 1872. A post office on the latter location was known as Gypsum from 1902 to 1905. History Carbon is located on the Middle Nodaway River. This was home to the Pottawatomie, Oto and Iowa Indian tribes, until the treaty of 1851 forced their removal to Kansas or Indian Territory, now known as Oklahoma. The first settler to Carbon was Elijah Walters, who established a sawmill there in 1849. He reported seeing huts and old camp fires but stated that the tribes had moved on, only to see an occasional "red man" appear and look over old camp sites and burial sites, then move on. Elijah built a mill on the Middle Nodaway river that became a great social center of its time. The village was originally named Walters, after its first settler, but was renamed Carbon after the discovery of coal. The town was established in 1873, but was not incorporated until 1903. A post office was established in Carbon in 1874, but from 1877 to 1880, the name was changed to Shinn. By the time of the Civil War, there were small coal mines along the riverbanks near Carbon. In 1894, there were nine coal mines in Carbon, of which five were then in use. Typical mine shafts were 80 feet deep, working a coal seam 12 to 20 inches (30 to 50 cm) thick. The town at that time was described as a mining camp. Unlike the vast majority of Iowa's coal camps, the UMWA had no union local in Carbon between 1900 and 1912; during that period, most of Iowa's coal camps were organized, and the largest UMWA locals in the country were based in Buxton and Centerville, Iowa. By 1908, it was estimated that the total coal production of the county had exceeded 350,000 tons, despite the lack of any rail connections. Most of this was from the Carbon area. Coal from the Carbon mines was sold locally, with some sold as