John, Robert and Thomas McCredie lived and worked as masons and joiners in northern Pyrmont in the 1860s, well placed to take advantage of the industrial transformation that followed the gold rushes. In 1868 Thomas took a lease on a parcel of land that Edward Macarthur had failed to sell, and began quarrying stone for his building projects. The boom in public building in the 1870s brought projects to build government offices and the general post office.
McCredie Brothers first expanded their quarries, but soon shifted their focus from quarrying – which they left to the Saunders family – to building. As John and Robert moved on, Thomas brought in William, Alexander and Andrew. The family could now afford to be patrons of religious and charitable causes. They also diversified their interests. Another Pyrmont McCredie – the architect George – helped design the redevelopment of Darling Island in the 1880s.
In 1879, the McCredie brothers donated a music hall in Harris Street to accommodate 500 people. It was used particularly by the Church of England school.
In the 1890s, Andrew McCredie was a Justice of the Peace, and a returning officer for Denison division.