Joseph Leatherland, son of John Leatherland and his wife Anne, served in the Eastern Cape in Graham's Horse from December 1851 to December 1852, when he was transferred to the Albany mounted police. In July 1855 he joined the Frontier Armed and Mounted Police, and in July 1856 was promoted to sergeant and put in command of a station. Promotion to sub-inspector followed in November 1860. In July 1877 he became quartermaster, with the rank of inspector, and in August the next year quartermaster with the rank of captain in the Cape Mounted Riflemen. In 1895 he was promoted to major and was still quartermaster of the regiment. He was married to Elizabeth H. Wallace.
Inspector Leatherland of the mounted police donated a pair of jackals, an eagle and a hawk to the Albany Museum, Grahamstown, in 1860, followed by 52 bird species and some mammals in 1861. He followed this up with a few more mammals from various places in the Eastern Cape in 1864, but was named John Leatherland in the museum's annual Report. Three years later, in October 1867, "Mr Leatherland" was elected a member of the Albany Natural History Society, which had been founded in Grahamstown in July that year.
He was married to Elizabeth Hunter, born Wallace, with whom he had two daughters.