He was Member of Parliament (MP) for constituencies in County Antrim from 1903 to 1929, taking his seat in the House of Commons of the United Kingdom.
The son of James Craig, of Craigavon, Belfast, a self-made millionaire whisky distiller, among his brothers was Northern Ireland's first Prime Minister, James Craig.
Craig first stood for Parliament at a by-election in 1903 for the South Antrim constituency, after the sitting Unionist MP William Ellison-Macartney had left the Commons to take up the post of Deputy-Master of the Royal Mint.
Although it was never formally abolished, the Irish Privy Council effectively ceased to exist with the creation of the Irish Free State, and on 12 December, ten members were sworn of a new Privy Council of Northern Ireland.
[6] In the 1922–1924 Conservative Government, led by Bonar Law and then Stanley Baldwin, Curtis was appointed in February 1923 as Parliamentary Secretary to the Minister for Pensions, and held that post until first Labour government took office in January 1924.