Botanist on Oxley's 1817 expedition

Cunningham joined John Oxley's 1817 expedition beyond the Blue Mountains to the Lachlan and Macquarie rivers and shared in the privations of the 1,200 miles (1,930 km) journey. He collected specimens of about 450 species and gained valuable experience as an explorer. Cunningham named the species Acacia pendula and Eucalyptus dumosa during this expedition.

Botanist on P.P. King's 1817-1822 circumnavigation voyages

Cunningham traveled as the ship's botanist aboard HMS Mermaid under Phillip Parker King from 1817 to 1820.^[3] The Mermaid was of only 85 tons, but sailing on 22 December 1817 they reached King George Sound on 21 January 1818. Though their stay was short many specimens were found but the islands on the west coast were comparatively barren. Towards the end of March the Goulburn Islands on the north coast were reached and many new plants were discovered. They reached Timor on 4 June 1818 and, turning for home, arrived at Port Jackson on 29 July 1818. Cunningham's collections during this voyage included about 300 species.

Shortly after his return, Cunningham made an excursion south from Sydney, ascending the prominent peak of Mount Keira overlooking the Illawarra region and present day Wollongong. Towards the end of the year he made a voyage to Tasmania arriving at Hobart on 2 January 1819. He next visited Launceston and though often finding the botany interesting, he found little that was absolutely new, as Brown had preceded him. In May he went with King in the Mermaid on a second voyage to the north and north-west coasts.^[1] On this occasion they started up the east coast and Cunningham found many opportunities for adding to his collections. One of these was after the ship reached the mouth of the Endeavour River (the site of modern Cooktown) on 28 June 1819.

The circumnavigation of Australia was completed on 27 August when they reached Vernon Island in Clarence Strait. They again visited Timor and arrived back in Sydney on 12 January 1820. The third voyage to the north coast with King began on 15 June, but meeting bad weather the bowsprit was lost and a return was made for repairs. Sailing again on 13 July 1820 the northerly course was followed and eventually the continent was circumnavigated. Though they found the little vessel was in a bad state when they were on the north-west coast, and though serious danger was escaped until they were close to home, they were nearly wrecked off Botany Bay. The Mermaid was then condemned and the next voyage was on the Bathurst which was twice the size of the Mermaid.^[1] They left on 26 May 1821, the northern route was chosen, and when they were on the west coast of Australia it was found necessary to go to Mauritius to refit, where they arrived on 27 September 1821. They left after a stay of seven weeks and reached King George Sound on 24 December 1821. A sufficiently long stay was made for Cunningham to make an excellent collection of plants, and then turning on their tracks the Bathurst sailed up the west coast and round the north of Australia. Sydney was reached again on 25 April 1822. Cunningham provided a chapter on botany to King's Narrative of a Survey.^[4]

1823 exploration for a pass over the Liverpool Range

In September 1822 Cunningham went on an expedition over the Blue Mountains and arrived at Bathurst on 14 October 1822 and returned to Parramatta in January 1823. His account of about 100 plants met with will be found in Geographical Memoirs on New South Wales, edited by Barron Field, 1825, under the title "A Specimen of the Indigenous Botany ... between Port Jackson and Bathurst".^{[citation needed]}

Cunningham soon became more interested in expeditions of discovery than botany and in 1823 he set out from Bathurst to explore inside the Great Dividing Range.^[5] With five men and five horses, he journeyed north from Bathurst, along the Cudgegong River, passing through what is now Rylstone and Coolah and then eastwards looking for a pass through the Liverpool Range. Unable to find one, he returned west through what is now Merriwa and then north to the base of the ranges there. On 7 June, after some difficult climbing, he came across a gap in the mountains which he named Pandora's Pass, which he thought would allow for a practicable road to the Liverpool Plains.^[6] This pass was soon superseded however by more accessible passes found to the east. He returned to Bathurst through an undeveloped Mudgee on 27 June 1823.^[7]

Cunningham also undertook an expedition to what is now Canberra in 1824. He travelled with three convicts, three horses and a cart and he travelled via Lake Bathurst, Captains Flat and the valley in which flows the Queanbeyan River. Poor weather prevented him from continuing his journey south.^[8]

Voyage to Moreton Bay in 1824

In September 1824 Cunningham accompanied John Oxley on his second expedition to Moreton Bay and explored up the Brisbane River.^[9]

Voyage to New Zealand in 1826

Cunningham had long wished to visit New Zealand and on 28 August 1826 he was able to sail on a whaler.^[1] He was hospitably received by the missionaries in the Bay of Islands, was able to do much botanical work, and returned to Sydney on 20 January 1827. Accounts of his work in New Zealand will be found in Hooker's Companion to the Botanical Magazine, 1836, and Annals of Natural History, 1838 and 1839.

1827 exploration of discovery to the Darling Downs

In probably his most famous expedition, Cunningham set out to explore the area to the west of Moreton Bay in 1827, crossing to the west of the Great Dividing Range from the Hunter Valley and travelling north. On this journey, Cunningham named many geographical landmarks including the Dumaresq River, Macintyre River, Condamine River, the Darling Downs, Mount Dumaresq and the Burrell or Gwydir River. He wrote in his diary that the lush grassland plains on the Darling Downs were ideal for livestock grazing. Exploring around Mount Dumaresq, Cunningham found a pass, now known as Cunninghams Gap.^[10]

Further exploration of the Moreton Bay region

Cunningham returned to the Moreton Bay penal colony in 1828, setting off from Brisbane with Patrick Logan, Charles Fraser and five men to find Mount Warning and to establish the route to Cunningham's Gap which he did, on 24 July.^[5] The peaks on either side of the gap were also named, Mount Cordeaux and Mount Mitchell. After exploring the McPherson Range area, Cunningham travelled on the south side of the Gap whereas the highway today runs further north, through the gap, from the small township of Aratula. Spicer's Gap which runs parallel to Cunningham's Gap was actually the pass first identified by Cunningham in 1827.^[11] After its rediscovery in 1847, Spicer's Gap was used as a stagecoach route. In 1829, Cunningham explored the Brisbane River.