Trinity's history may be traced to Scottish families arriving in St. Louis. On March 10, 1840 these sturdy people, who settled in St. Louis only a year before, organized the First Associate Reformed Church of St. Louis. The following year, they laid a cornerstone for a church at Broadway and Locust, the present site of the Federal Reserve Bank. In this young city where two-thirds of the residents were Catholic, this group of Scotch Covenanters saw their church as the dominating influence in their life. They believed, as we do today, that God's grace is for everyone and they were aggressively anti-slavery - even though they were three blocks from the Court House where slaves were being sold at public auction to the highest bidder.

In 1858, the United Presbyterian Church denomination was formed in Philadelphia, and the First Associated Reformed Church of St. Louis became the First United Presbyterian Church of St. Louis. From that time forward, it was to carry on the work and spirit of that first Associated Reform congregation ever to be established west of the Mississippi River.

When the Singer Sewing Machine Company bought the church property in 1873, the congregation moved to a new building at the corner of Nineteenth and Morgan streets. The new building was erected for $55,000. Twenty years later, the church moved to Newstead and Morgan where a new church building was again erected. That site was sold in 1919 to another congregation and the new site of First United Presbyterian Church of St. Louis - at 6800 Washington Avenue - was dedicated on December 7, 1922.

A similar history was evolving with the Lucas Avenue Cumberland Presbyterian Church, established on February 6, 1878. This congregation merged with the Kingshighway Cumberland Presbyterian Church in 1908. Kingshighway Presbyterian, located at the corner of Kingshighway and Cabanne, merged with the First Presbyterian Church of North America on Washington Avenue in University City on June 21, 1953. The name of the new merged church was chosen to be Trinity Presbyterian Church. As a part of this merger, the church building was expanded to include a new chapel, additional church school facilities, a nursery, and enlarged church offices.

Much like its very first ancestors, Trinity today continues to believe that God meets all of us wherever we are and as we are. All who come are welcomed into the same circle of God's unconditional love. Trinity continues to put its faith into action with a deep commitment to mission. Many of the essential social services in the community have roots to Trinity: Youth Emergency Service; the English Language School; U. City Residential Service; and SHED (Safe Housing for the Elderly and Disabled). Trinity shares the hands and hearts of its members as well as its financial blessings with a multitude of essential organizations.