McCay, Sir James Whiteside (1864–1930), politician and soldier, was born 21 December 1864 in Ballynure, Co. Antrim, eldest of ten children of the Rev. Andrew Ross Boyd McCay, presbyterian minister, and Lily McCay (née Brown). When James was one year old, the family emigrated to the colony of Victoria, Australia. He began his education at the local state school in Castlemaine, about 100 km north-west of Melbourne, won a scholarship to Scotch College, Melbourne, and entered Ormond College, University of Melbourne (MA 1894, LLM 1897). McCay was principal of Castlemaine Grammar School from 1885, and set up a legal practice as soon as he completed his qualifications. However, he was best known as a soldier and politician.
McCay was able to combine these twin careers because at this time most Australian army units were part-time militia. He enlisted in the 4th Victorian Rifles in 1880 and was commissioned in 1886; and was elected to the Castlemaine borough council in 1890 and entered the Victorian parliament in 1895 after winning a by-election by ten votes. He was defeated in the November 1900 elections, but the federation of the Australian colonies in January 1901 offered the opportunity for a quick return to public life. He won a seat in the inaugural federal parliament and served as defence minister from 18 August 1904 to 5 July 1905. McCay took no part in sectarian debates. He did not speak in October 1905 when the Australian house of representatives debated sending an address supporting Irish home rule to King Edward VII. McCay raised several points of order in an attempt to stop the motion being voted on (it was passed 33 to 21) probably out of a desire to avoid divisiveness.
Defeated in the 1906 election, McCay was promoted on 6 December 1907 to colonel and took command of the newly formed Australian Intelligence Corps. On the outbreak of the first world war he was initially put in charge of censorship in Australia, but on 15 August 1914 he was appointed to command the 2nd Brigade of the Australian Imperial Force (AIF). Wounded at Gallipoli in 1915 and invalided to Australia, McCay was promoted to the temporary rank of major-general and appointed inspector-general of the AIF in Australia. When the AIF was expanded to five infantry divisions, McCay took command of the 5th Division on 22 March 1916. The 5th was the last Australian division to arrive on the western front, but became the first to see action when it made a feint attack on Fromelles during the Somme offensive on 19 July 1916. The badly planned operation cost the division 5,500 casualties. In January 1917 McCay left France and spent the rest of the war in charge of AIF depots in the UK. For this work he was appointed KCMG (1918) and KBE (1919). He was later business adviser to the Australian government (1919–22).
McCay's sarcastic manner made him perhaps the most unpopular commander in the AIF. His men, and later the general public, blamed him for the Fromelles disaster and some other incidents. When the volume of the Australian official history covering Fromelles was published (1929), it made the point that the decision to attack Fromelles had been made by McCay's superiors, and that it was therefore unjust to blame him for the failure. McCay had never once publicly defended himself, but wrote to the official historian, C. E. W. Bean, that after ten years of feeling the barbs of personal attack, he felt he had been vindicated by history. He died on 1 October 1930.
McCay married (8 April 1896) Julia Mary O'Meara, daughter of the police magistrate at Kyneton, near Castlemaine. They had two daughters. McCay's papers have not survived, but a portrait is held by the Castlemaine Art Gallery.