On 31 May 1827 Frederick I'Ons married Ann Frazer, whose ill-health led in 1834 to the young couple's emigrating to the Albany district of Grahamstown.
This date marks the first of his 'Aquila Caricatures', a series of informative though jocularly offensive barbs directed at Andries Stockenström, the lieutenant governor of British Kaffraria at the time.
The patrons of I'Ons were largely military types who commissioned portraits of the local Xhosa chiefs, such as Sandile and Khama.
The images of these 'native characters' are regarded as his most important works, reflecting a great deal of sensitivity and skill in their portrayal, and likened to those of Adriaen van Ostade.
He eked out his income by painting stage decor, portraits of notable Grahamstown residents and giving art classes.