The Mercersburg Society was founded in 1983 by a group of pastors, professors, church judicatory persons and laity for study and discussion of matters of contemporary theology within the context of Mercersburg Theology, a theological system of thought developed by John Williamson Nevin and Philip Schaff from 1840-1860 at the Seminary of the German Reformed Church in Mercersburg, Pennsylvania.

The membership of the Society is open to laity and clergy, with the current membership around 125 from a number of different denominations, including the United Church of Christ, Unitarian-Universalist, Episcopal Church, Reformed Church in America, Evangelical Lutheran Church in America, Presbyterian Church (U.S.A.), Mennonite Church, Christian Church (Disciples of Christ), and the United Methodist Church.

The Society organized a theological gathering in 1984 with a group called the Biblical, Theological, Liturgy Group at Craigville, Massachusetts and had its first Mercersburg Convocation, an annual two-day event for members and friends of the Society to study and discuss theology and Mercersburg, in 1985 at St. John's United Church of Christ in Chambersburg, Pennsylvania.

Following the 1985 Convocation, The New Mercersburg Review, the journal of the Society, was started and is published twice a year. A newsletter of the Society has been published at least once a year since 1986.

From 1991-2000, a Theological Forum of the Society convened to gather together members and friends of the Society to discuss theology and produce documents responding to specific theological concerns of the Church today.

The income of the Society is primarily derived from membership dues of $35.00 per year, life memberships of $300.00, and private donations.

The Corporate Board of the Society meets annually before the Convocation to approve a budget and to make other necessary decisions for the operation of the Society. An Executive Committee meets two to three times a year between Board meetings to conduct the business of the Society.