Extensive emigrations from the northern counties of Ireland by the Scots who had been established there were principally made at two distinct periods of time: the first, from about 1718 to the middle of the century and the second, from about 1771 to 1773. These Scots-Irish emigrants landed principally at New Castle and Philadelphia and found their way northward and westward into the eastern and middle counties of PA. The 1st settlement of Scots-Irish within the present bounds of Chester county was made about the year 1718. They "planted" Presbyterian churches at Upper Octorara, Fagg's Manor, Brandywine Manor, New London and Oxford.
The oldest Presbyterian Church in Chester County is "Great Valley" in Tredyffrin twp, where there was a congregation as early as 1710, but it was not regularly organized until 1714.
Upper Octorara Church, in Sadsbury Township, one mile north of Parkersburg, was organized in 1720. The prefix Upper was subsequently given to distinguish it from Middle Octorara, in Lancaster County. The region of the country where Fagg's Manor Church is situated was largely settled by Scots-Irish Presbyterians, and from the first the church has been a strong one. It dates from 1730, previous to which time those who organized it worshipped at Upper Octorara. The church edifice is located in the NW corner of what was called Sir John Fagg's Manor and first called New Londonderry from the township in which it is located...that name soon gave way to Fagg's Manor.
The Rock Presbyterian church was organized in 1720, and has been referred to as "the Rock" since 1787.
The New London church was constituted in 1728.
The Doe Run Presbyterian Church was organized into a congregation in about 1740.
Unionville Presbyterian church was organized in 1829.
Brandywine Manor, ecclesiastically known as Forks of Brandywine, was constituted in early times as a part of what later became Upper Octorara. Originnally under the care of the Rev. Adam Boyd, it was organized as a separate congregation in 1735, when a house of worship was erected. The early dwellers of Oxford worshiped in other churches, but erected their own in 1725 to 1730.
Nottingham Presbyterian church dates from 1802.