Inspired in 1925 by hearing cartoonist Will Dyson speak on political satire and visiting his studio,[7] he enrolled in night classes at the Working Men's College, and then the National Gallery School (1926–1935).

[7] Having written a critique of William Dobell's 1943 The Billy Boy for the Argus, McCulloch was hired as its art critic from 1944 until 1947,[8] and after the Second World War during which his artist brother Wilfred was killed fighting in the fall of Singapore, Alan became art editor under George Johnston of a new Argus weekly national magazine, Picture Post, to which he was also appointed as a cartoonist.

[9] Aspiring to the quality and status of the German cosmopolitan magazine Simplissimuss they published major Australian writers and commissioned illustrations from the 'Dunera boys' Frederick Schonbach, Erwin Fabian [de] and Klaus Friedeberger, and other artists including Albert Tucker and Noel Counihan.,[10] but after three years were laid off for their even-handedness in ignoring directives requiring a bias against left-wing artists,[7] when it became the Australasian Post with a very different ethos.

[12]Johnstone departed for Greece, and McCulloch to the United States from Sydney on the SS Marine Phoenix, accompanied by his mother Annie and a friend Gavin Casey.

Until 1949 he and his wife toured America, meeting Marcel Duchamp and other Surrealists, and McCullloch recorded their travels in Highway Forty[14] while also writing magazine articles.

After the death of Ellen his wife for 45 years, McCulloch, after recovering from an operation and suffering from Parkinson's disease, moved in March 1991 to a retirement home in Kew,[6] and in his remaining months resumed making art and continued his friendships with visits from Louis Kahan, Albert Tucker and Andrew Sibley, and with his daughter Susan he worked on the 3rd edition of their Encyclopedia.

[6] Top price paid was $9000 for one of two oils by John Peter Russell, while Tom Roberts' blographer Andrew McKenzie bought The Australian Impressionist’s palette for $1200.

[27] McCulloch died in the aged accommodation on 21 December 1992,[28] and was remembered as a stalwart champion of modernism for his Encyclopedia, and for his newspaper and magazine reviews defending and promoting work of Charles Blackman, John Brack.

Leonard French, Julius Kane, Roger Kemp, Inge King, Clifford Last, Clement Meadmore, John Perceval, Clifton Pugh and Fred Williams.

Though sceptical of color field abstraction, he nevertheless supported its individual proponents Sidney Ball, Janet Dawson, Robert Jacks and Jan Senbergs.