Ship broker. Educated at the elementary English School and at the Grammar School, St Andrews. Employed as a ship-broker and commission agent, then entered a lawyer's office and not finding this to his liking became, in 1839 legal adviser to Adam Thom, first recorder of Rupert's Land, Red River Settlement, Canada. Joined the Hudson's Bay Company and became a Commissioned Officer. In 1850 was the chief trader at the Company's factory at Fort Garry. Became a Member of the Red River Settlement's Council and President of the Petty Court in 1851. For some time was a tenant of a farm belonging to John Robertson near Scone. Moved to Sydney in 1857, and became a partner in Mollison & Black, ship-brokers and commission agents, handling the movements of Chinese immigrants. Was Chairman of the Land League (which was pressing for a thorough reform in the administration of the land system) in 1856, at the inception of responsible government for New South Wales; soon after, was asked to stand for Parliament. The aims of the Land League, together with an elective Upper House, railway extension, retrenchment in the government's expenses, reform of the immigration system, and a National system of education, formed the basis of his policies. With James Martin, Henry Parkes and Charles Cowper, was elected for East Sydney on 9 June 1859. Black became Secretary for Lands in William Forster's administration from 27 October 1859 to 8 March 1860. Did not seek re-election after the dissolution of Parliament in November 1860 and returned to Scotland in 1862. Went to Canada again where he was appointed recorder of Rupert's Land until 1870, when the province of Manitoba was created. Was a member of the delegation of Red River settlers to Ottawa in 1870.