The church now known as the Old South Congregational Church in Hallowell, Maine first gathered on February 25, 1790 as the Congregational Church of Christ of Chester Plantation. It was the second church in the area of Hallowell, which in 1790 consisted of the present towns of of Hallowell, Augusta, Chelsea, and parts of Manchester and Farmingdale. Several of the church leaders resided in Chester and joined with the Hallowell members to form the church, largely in opposition to the doctrine being preached by the Rev. Isaac Foster, a minister of the church at "the Fort".

The next year a number of other members of that church joined with the Chester Church "if it's name might be altered...to be ever after denominated Congregational Church of Christ in Hallowell."

In 1794 the town was divided into the South, Middle, and North parishes, thereby creating a situation where the people had full liberty to attend and join the church in the Parish of their choice, regardless of the part of town in which they resided. Registration with the Clerk of the Parish was required to determine where takes would be paid. Those who were members of the Chester Church "chose to fall into the South Parish."

Soon the town was again divided, the Middle and North Parishes became Augusta and the Middle Parish was renamed the South Parish of Augusta. The old South Parish was called Hallowell. The church was then called South Church, commonly referred to as the Old South Church.

The Parish was the town of Hallowell. Initially it was the Parish that hired the minister upon approval by the Church and raised the funds to build the meetinghouse, along with all the other duties required by town government. Thus, the Parish and Church Societies were very separate organizations - each with its own members and officers. With time, when other churches had become established in Hallowell, the Parish Society became responsible only for the raising of pledges and the care of the South Church meetinghouse. The Church Society took care of the church, hiring the minister and providing worship services. Not everyone became Church members, only those whom it was judged had been chosen by God to be worthy.

Thus, when the old meetinghouse burned, it was the Parish members who were responsible for rebuilding the church. It was not until 1952 that the Parish and Church became one, incorporated as the Old South Congregational Church, Hallowell, Maine.