St. Mary's history begins with the Columbia Detachment of the Royal Engineers or Sappers who were sent from Britain in 1858 to build roads and keep the peace in the newly formed colony of British Columbia. The Royal Engineers were based in what is now Sapperton, where Anglican services for the Sappers and their families were held in a portion of the barracks. Originally under the care of the military chaplain, the congregation was assigned a Priest-in-Charge in September 1862. Following the disbanding of the Columbia Detachment in the summer of 1863, however, the young congregation had to find a new home. The new church of St. Mary the Virgin was designed and built by former Sappers, and was consecrated May 1, 1865.
At that time, New Westminster was the capital of the new colony and Government House stood nearby near the current intersection of Columbia and Richmond Streets. Because of its proximity to the seat of power, St. Mary's was regarded as highly fashionable, and Governor Frederick Seymour was one of the earliest worshipers at St. Mary's. The pew set aside for the Governor and his family survives at the front of the nave, marked with a memorial plaque.
This state of affairs was not to last, as in 1868 the capital was moved to Victoria, taking most of St. Mary's congregation with it and leaving the church to be a small rural parish at the edge of the forest on the outskirts of town.
In 1879 the Diocese of New Westminster was formed, encompassing the southern half of mainland British Columbia. The first bishop, the Rt. Rev. Acton Sillitoe, arrived from England the next year and chose St. Mary's as his base. Bishop Sillitoe and his wife took up residence in St. Mary's Mount, the church rectory that stood near the current intersection of Cumberland and Sapper Streets, and transformed it into one of the social centres of the young city. Over the next nine years three Governors General (the Marquis of Lorne, the Marquis of Lansdowne and Lord Stanley of Preston), as well as Prime Minister John A. MacDonald, stayed at the Bishop's residence on their visits to New Westminster. In 1889, the bishop moved his base of operations to Holy Trinity in downtown New Westminster, ending St. Mary's second period of prominence.
St. Mary’s in 1898, with Rev. John Davis and ex-Royal Engineer Charles Digby.
Since that time, that church has been extended twice to accommodate growth, and once in the mid-thirties it had to be partially rebuilt following a near-disastrous fire that destroyed the roof and damaged part of the interior. Through all this, the church's original charm has been preserved.
Today St. Mary's is one of the oldest continuously used church buildings in the province. The interior of this heritage building is finished throughout in rich natural cedar, showing clearly why Bishop Sillitoe declared it “a model of what all wooden churches ought to be”. Many beautiful stained glass windows and other fine memorials attest to the love and devotion given to St. Mary's by its faithful members over the years.