Arnold Clement Whalan established A.C. Whalan & Co Pty Ltd and commenced trading in 1939, the business traded as a stock and station agent with business involvement primarily in agricultural activities, such as the supply of rural produce, fencing and feed. The nature of the business lead to the supply and delivery of grain and dry feed to both the local farming community and mining industry. At the time Pit ponies were used to supply the transport muscle to haul the hand dug coal in dolly cars to the surface of the underground mines in Lithgow and the surrounding area. This is where A.C. Whalan & Co Pty Ltd commenced it association with the mining industry.

The involvement in the mining industry grew steadily, with the resurgence of the resources industry in 1970's and 1980's the company took advantage of its location and known customer service. A.C. Whalan & Co Pty Ltd's original site located at Lidsdale in the Lithgow area was ideally situated to service the Western coalfields and during this period mining and industrial supplies became the core business of the company as manufactures approached A.C Whalan & Co to be their distributors and representative. Pipes, valves and fittings, soon became the major focus, and customers were established in Wollongong, Newcastle, the Hunter Valley, and the emerging Queensland Bowen Basin.

With service and locally held stocks being considered a priority in allowing us to service our customer requirements, the Singleton branch was opened in 1985. Continued growth on the back of an expanding customer base in both the mining and civil infrastructure sectors resulted in A.C. Whalan & Co opening its first branches in Mackay in 1992. Exploration, development and the reopening of the Namoi Valley coal reserves provided the opportunity for A.C. Whalan & Co to open the Gunnedah branch in 2008. After the award of a PFV contract and the long term outlook for the Southern Galilee basin the requirement for a second Queensland branch saw Emerald open in 2013.