The United Supreme Grand Chapter of Mark & Royal Arch Masons of NSW &ACT came into existence on 18th. October, 1980, when the Supreme Grand Chapter of Royal Arch Masons of New South Wales, the Grand Mark Lodge of New South Wales, the Royal and Select Masters of New South Wales and the Scottish Royal Arch District of New South Wales were amalgamated and constituted to form the United Supreme Grand Chapter of Mark and Royal Arch Masons of New South Wales and The Australian Capital Territory. Up until then Capitular Masonry as these Degrees and Orders were often known was very different in New South Wales and the Australian Capital Territory.
In the 19th Century, lodges and Chapters were warranted in N.S.W. by Grand Bodies in Ireland, England, and Scotland. The Charters granted in NSW were grouped for Administration purposes into either Provinces or Districts. Following the formation of the Grand Lodge of NSW in 1888, the English Chapters lost association with their English Lodges to which they were compulsorily attached, and so in 1889 the Supreme Grand Chapter of Royal Arch Masons of New South Wales was formed to address this situation and a sovereign body recognized worldwide came into existence.
The English Constituted Mark Lodges decided to remain separate from other Jurisdictions, as is the case in England, Victoria and South Australia and so the Grand Lodge of Mark Master Masons of New South Wales was established in 1889, and was recognized worldwide.
The Scottish Chapters remained as part of Scottish Royal Arch masonry as a Province and later as a District for New South Wales.
At the Union these bodies joined together to form the United Supreme Grand Chapter of Mark and Royal Arch Masons of NSW & ACT.