Sam Hughes joined the Canadian militia as a boy, and fought against the Fenian raids in the 1860s and 1870s. He was elected to Parliament in 1892, and fought in the Boer War in 1899 after helping to convince Wilfrid Laurier to send Canadian troops. As a member of Parliament he was unpopular with Catholics and French-Canadians because of anti-Catholic remarks he had made in a newspaper. However, he was appointed Minister of Militia after the election of Robert Laird Borden in 1911, with the aim of creating a distinct Canadian army within the British Empire, to be used in imperialistic wars.
He encouraged recruitment of volunteers when the First World War broke out in 1914, and constructed a training camp in Valcartier, Quebec. He oversaw the training of the soldiers and within three weeks they were ready to depart, although he first thought it necessary to deliver a lengthy, patriotic speech on horseback.
Hughes insisted on equipping Canadian soldiers with the Canadian-made Ross rifle, an inferior weapon that frequently misfired, became easily jammed with mud or its bayonet falling off easily. Hughes and Sir Charles Ross, the inventor of the gun, remained loyal to their gun, but Borden authorized its replacement by the British Lee-Enfield rifle. 1452 Canadian soldiers promptly disposed of them as they preferred the Lee-Enfield rifle, including General Arthur Currie, whom Hughes already disliked. Currie had been an old friend of Hughes' son Garnet, but felt Garnet was not a capable soldier. When Currie took command of the army he would not allow Garnet to serve under him. However, Currie was considered a war hero, and Hughes' calls for Currie's removal were ignored.
Hughes also erred in creating a committee in London to give orders to the Canadian army overseas, something that could only legally be done by the Cabinet in Ottawa. Borden created a London branch of the Cabinet to overcome this problem, but left Hughes out of it, which prompted Hughes to voice his opposition in a highly publicized letter to the Prime Minister. Borden had no choice but to dismiss him from his post on November 9, 1916. Hughes remained in government as a minor figure, and died in 1921. Hughes was knighted on August 24, 1915.