Creswell worked as a mining engineer in Venezuela, Asia Minor, Rhodesia and the Transvaal before becoming manager of the Durban Deep Mine, at Roodepoort. At the outset of the Second Boer War in 1899 he was commissioned as a lieutenant in the newly raised Imperial Light Horse. When mining on the Witwatersrand began again, he became General Manager of the Village Main Reef Mine. After strongly opposing Chinese labourers being imported to the Transvaal, he resigned as manager in 1903, going on to take a leading role in the campaign to end the use of Chinese labour and “became the champion of the white labourer”, advocating the use of white labour, and white immigration, as the solution to South Africa's labour problems.