The United Church was founded on ecumenical principles to serve the needs of various denominational backgrounds in the early history of Los Alamos. The United Church was the first protestant church organized in Los Alamos, formally established in 1947 with 184 charter members.

The United Church facilities grew out of an Army Chapel moved by the Atomic Energy Commission from a Santa Fe military hospital in 1947. In Los Alamos, it originally served as a house of worship for Protestant, Catholic and Jewish faiths, as well as providing housing for a Catholic priest. In 1955 the church moved its Sunday School into the first building completely financed by the congregation, an Army domitory which was moved near the chapel. On November 22, 1955, the congregation completed negotiations and assumed title to the chapel building, upon payment of $12,500. The Christian Education Building, which replaced the old dormitory, was compelted in 1966. All currently-owned land was purchased on November 21, 1967. Craig Hall was dedicated in 1972 and the manse was built in 1979.

Over the years, The United Church has grown from approximately 200 members in 1947 to over 700 in 1999. The annual budget has increased from approximately $16,000 in 1948 to over $600,000 in 1999, with about 1/4 of that amount used for mission service. Our church was established and has been financed by the people of Los Alamos from its inception. Our material growth has been paralleled by a significant spiritual growth. The United Church is governed by the congregation and presided over by a lay moderator elected annually and numerous working boards and committees.