William purchased Crawfordsburn Estate from Lord Clanbrassil in 1670*. His will, made in 1678, mentions Ursula. It is not known for sure whether she was his wife or his sister. William, a Protestant landed proprietor, was a Colonel in the Union Regiment of Volunteers and was for many years M.P. for Lisburn, (near his seat of Moira Castle), in the Irish Parliament.

*It should be noted that Sir James HAMILTON of Killyleagh and Bangor, Serjeant at law and Privy Councillor to James I was created by patent dated 4 May 1622, 1st Viscount Claneboyne. His son and heir James, 2nd Viscount Claneboyne was created Earl of Clanbrassil, 4th March 1647 and was father of Henry, 2nd Earl of Clanbrassil who died d.s.p. 1675.

The relationship between William CRAWFORD and Andrew CRAUFORD, the original tenant of this property is not definitely established, but is assumed to have been close. They may have been father and son. There is also the indication that William had a brother Andrew, who was father to his daughter-in-law Jane.

WARNING ! It should be noted that the early generations of the CRAWFORD tree are comprised of a patchwork built of snippets of information, which have been put together (with approximated dates) to form a logical whole. NO CREDENCE SHOULD BE PLACED ON THE ACCURACY OF INFORMATION WHERE THIS WARNING IS SHOWN!

It would appear that quite a lot of the Clanbrassil estates were sold about this time, as in 1671, The Cultra estate was sold to John Kennedy who married Martha Stewart and whose granddaughter Mary (Maria) later married in 1774, William's grandson John CRAWFORD