The Company was formed in 1824 to "extend and improve the flocks of Merino sheep" in New South Wales. The initial land grant at Port Stephens proved unsuitable and, in 1831, a proportion of this was exchanged for 101,000 ha at Warrah on the Liverpool Plains and 127,000 ha on the Peel River (eventually becoming known as Goonoo Goonoo). At the same time, AAco was involved in the development and operation of coalmines in the Newcastle area. Convict labour was used to develop both pastoral and mining operations. Shorthorn bulls were imported from England to develop company herds. Despite droughts and depressions and some heavy stock losses, by 1850 sheep numbers had risen to 114,118, cattle to 8,306 and horses to 1,436. Wool provided export income along with horse sales to India but cattle outlets were restricted to the domestic market.

Peel River joined the pastoral expansion to the north with properties acquired on the Clarence River and then into Queensland on the Darling Downs and on to Longreach.