Henry Simpson arrived in South Australia in August 1836 as second officer of the John Pirie one of the first of the immigrant ships. He was later made master of this ship but later left her to work with another ship before purchasing a small cutter and engaging in trade with Kangaroo Island. He subsequently part-owned a number of ships and by 1860 had established a coal shipping business in partnership with a number of men. Quick to take advantage of opportunities he chartered vessels to supplement his fleet and supplied coal to the copper smelters at Wallaroo and carried the copper ore to Newcastle.

He maintained coal hulks in Port Adelaide for supplying steamships and also for the production of gas lighting, and eventually himself operated steamships when he realised how easy it was to maintain a tight shipping schedule with these vessels. Late in his career Simpson moved into the passenger trade with his steamships Tenterden and Birksgate.

Henry Simpson was highly regarded in the South Australian shipping industry. His son JL Simpson joined him in the business which operated from Currie Street in Adelaide and from a small office on the corner of Commercial Street and St Vincent Street, Port Adelaide. This office gave rise to the corner being known as 'the Black Diamond Corner', a well known Port Adelaide landmark.

The Black Diamond Line of colliers declined as the mines at Wallaroo declined; the company was bought out in part by Australasian Steam Navigation Company and had ceased to exist totally by 1895.