[1] This open country had been carefully and deliberately maintained by the Aboriginal people in what has been called firestick farming, an annual pattern of controlled burns to protect certain resource areas and pasture for native grazing animals.

However, the squatters still had no permanency of land tenure, and in 1847 Orders in Council were introduced which allowed further 14 year leases for established unsettled runs on payment of an annual fee per head of stock.

The Orders in Council also gave the run holders the pre-emptive right to purchase the land for its fair value in an unimproved state at less than one pound per acre at the completion of the lease.

The 1846 diary of the New South Wales Commissioner for Crown Lands, Darling Downs District, stated the run was 120 square miles with 15,000 head of sheep, 400 cattle and 30 horses.

[1] In December 1851 and March 1852, the artist Conrad Martens (1801-1878), who had arrived in Sydney in 1835, stayed at Glengallan during the course of his five-month trip to the Brisbane area and the Darling Downs in search of painting commissions.

These drawings and paintings are some of the few illustrations of Queensland during this time, and his sketches of Glengallan show the main homestead as two timber buildings surrounded by verandahs and situated close together.

He gained pastoral experience in the Hunter River district and c.1842 drove sheep from Maitland to the Darling Downs for the Aberdeen Co, and later for the North British Australian Co. From 1844 he was overseer at Goomburra, and after two years with the support of Walter Grey of Ipswich, he bought Canal Creek well stocked with Talgai Merinos.

[1] The construction of Glengallan was supervised by Warwick builder Thomas Wood, possibly for architect Charles Balding who, based in Ipswich, had opened a temporary office in Toowoomba and his practice extended to the Darling Downs.

In early 1865 Deuchar had taken over sole control of the management of Glengallan, and contracted to buy the property by taking out a mortgage with Marshall payable in ten years.

The furniture, excluding the Dining Table for some reason, was deemed part of the insolvent estate and was sold for £250, which made up a major portion of the final settlement to unsecured creditors of £327 - 4½d in the £.

The large size of the roof tank was probably due to the type of toilet system used, a rare feature at the time, which had been invented in 1778 and required high water pressure.

The kitchen was built adjoining the side of the covered way, but separate from the stone house, and was set on stumps with a large chimney at its eastern end.

In the open areas fostered by the Aboriginal land management practices, prior to European settlement, a pasture dominated by nutritious grasses had developed.

After pastoral experience in New South Wales and Queensland, Slade married Sophia Thompson on 1 March 1873 at St Mark's Church of England Warwick, and that year became manager and partner of Glengallan.

Considerable pressures were put upon the pastoralists due to demand for smaller land holdings, eventually resulting in the Selection Acts of the 1860s and 1870s which forced them to borrow heavily, and the fluctuation of wool prices meant that it was difficult for them to make a profit.

St Andrew's was described as a weatherboard church that could accommodate 200 people, painted dark red with pale green glass casement windows and a vestry at the western end.

[1] By 1904 the structures at the head station consisted of Glengallan Homestead, with the rear cedar wing, kitchen and bath house attached, sandstone office/store, two storeyed stables, buggy shed, and servants quarters.

In the early 1930s the first floor of Glengallan House was unoccupied and the servants quarters, a long narrow timber building comprising rooms opening onto a verandah, was demolished.

[16][17] In 1946 the kitchen and bath house were removed to other parts of the property, and later that year the cedar wing was dismantled and sold to Eddie Mogridge of Tannymorel, and it has subsequently been moved to Swanfels.

The rear elevation has projecting sandstone blocks on the north and south ends, indicating the intended two-storeyed extensions which were never built and which would have formed a U-shaped plan.

The central entry has double doors with sidelights, and an arched fanlight with coloured glass segments surmounted by an expressed keystone carved in relief with the initials JD 1867 surrounded by a garland of leaves.

The ground floor north and south elevations have a projecting sandstone bay with a central French door flanked by a tall, narrow sash window.

These doors are accessed by rough sandstone steps and a timber ramp, and a stone lined stormwater drain is located in front of and running parallel to this wall.

The main bedroom, on the south, has a cedar fireplace surround and evidence of a shelving unit which was located between the chimney breast and adjacent wall but was probably not an original fitting.

Excavations have been undertaken to the site of the cedar wing and kitchen complex, stables, stormwater drains and sewerage system, and to a large part of the area north and west of the office.

Slade was also described as the archetypal Anglo-Australian patrician of Warwick, being a patron, office-bearer, benefactor and member of numerous societies, clubs, the Masonic Lodge and Anglican Church.

Although the homestead was built as part of a larger, uncompleted design, the grand architectural concept can be appreciated and, with its picturesque siting, the building is recognised as a landmark in the surrounding rural landscape.

Some elements of the building were technically innovative for the time, particularly the verandah louvre system and French doors with insect screens, reflecting a consideration for the Queensland climate and conditions.

As a ruin of a grand homestead, which has strong associations with the history and pastoral development of the Darling Downs, the building has unique aesthetic and cultural attributes and has been the subject of much community concern and recent conservation action, as reflected in its current administration by the Glengallan Homestead Trust Ltd.[1] The place has a special association with the life or work of a particular person, group or organisation of importance in Queensland's history.

[1] Slade was also described as the archetypal Anglo-Australian patrician of Warwick, being a patron, office-bearer, benefactor and member of numerous societies, clubs, the Masonic Lodge and Anglican Church.