The Illustrated Adelaide Post was South Australia's first fully illustrated newspaper. The monthly was founded by William Anderson Cawthorne, later of the well-known Cawthorne's music shop in Adelaide. Despite its title, the newspaper contained predominantly Victorian news and illustrations as it was run as a subsidiary of the Illustrated Melbourne Post. The local content was therefore minimal, usually consisting of a column of South Australian news on the front page, and one local illustration. Cawthorne was an early amateur anthropologist, and engravings based on his original artworks depicting Aboriginal subjects were frequently published in the newspaper. Cawthorne arrved in Adelaide in 1841, aged 16, with his mother. He was an artist, musician and teacher, and eventually opened one of the first boys' schools in Adelaide. In 1852 he was elected to South Australia's first Education Board. From 1865 he began contributing engravings, based on his drawings, to the Illustrated Melbourne Post. Two years later Cawthorne began this newspaper.

Content Early issues consisted of columns of news from the various states and New Zealand, as well as a theatre column, and articles about the illustrations. In the first two years occasionally a piece of 'original' music was included, usually printed on the back page. The news content was mostly Victorian, and leaned towards sensational news such as murders. Generally there was little editorial comment. However in 1868 the Post reported being criticised by the Register newspaper for a statement that the governors, "ought to be of the same religious opinion as the majority of the colonists over whom they preside." (25 March 1868, p. 48) This was at the time of the death of the Roman Catholic governor, Sir Dominick Daly.

Illustrations The illustrations cover a variety of subjects, including buildings, scenery, people, and Aboriginal subjects. Some, if not most, were clearly based on photographs, and sometimes this is noted, for example a view of Kapunda mines notes that it was taken from a photograph by ES Nixon. (22 June 1867, p. 82) Other illustrations, such as the destruction of the Torrens dam by flooding is noted as being from an original sketch by Cawthorne. (23 November 1867, p. 161) Occasionally a special coloured print was included as a supplement. The issue of 23 July 1867 was advertised as including a coloured double-page engraving of 'a native corroboree.' Unfortunately these supplements have generally not survived. Australia's first Royal Visit in 1867 saw the publication not only of sketches of Prince Alfred's arrival in Adelaide, done on the spot by Cawthorne, but also a special 'later edition' which included an extra drawing of Prince Alfred on a possum shooting expedition. (23 November 1867, p. 165) Fiji was a popular subject with many illustrations in 1871, and a monthly column of news from the islands in 1872. In 1872 there were only a handfful of South Australian illustrations.

Aboriginal content Cawthorne published engravings of many of his own sketches of Aboriginal customs and artefacts. Accused by a correspondent (George Mackie of Melbourne) of 'greatly misrepresenting the attempts at evangelising the Aborigines,' he responded:

... It is notorious to anyone who takes the trouble to unquire, that all the attempts to civilise the aborigines have been utter failures. We have had a much longer experience than Mr Mackie can possibly have had ... (12 August 1868, p. 119)

Owners From the issue of June 1868 the format was changed slightly, with the back page in a different type-face, suggesting the newspaper was possibly being printed in Victoria, with only the back page printed by Cawthorne in Adelaide. Previously the printers were given as W. Hay of the Advertiser, but from July 1867 as Walter Sims and Joseph Elliott. The new style from June 1868 gave Cawthorne as both printer and publisher. From December 1869 the printer was James Heath Lewis. In July 1872, Webb, Vardon and Pritchard became the printers, and from October 1872 by Walter Cousins Sims. In November 1873, Webb, Vardon and Pritchard were again the printers.