"In 1740, the uninclosed lands on the North side of the River, denominated Sealand, amounted to 4,818 acres." [From A Memoir of Hawarden Parish, Richard Willett, 1822]
During the eighteenth century, in an attempt to assist navigation to Chester, the River Dee to the west of Chester was diverted into a man-made channel, some distance south of its former course. The Flintshire/Cheshire border still follows the former line of the river. An extensive area of marshland, within the parish of Hawarden, but to the north of the new channel, was reclaimed as a result of this diversion. This reclaimed area became known as Sealand.
The district church of St. Bartholomew, at Sealand, in the parish of Hawarden, was consecrated on the 15th of October 1867.
"The church is designed in the Early Gothic style. It is constructed of stone from the Helsby quarries, the interior being finished with ashlar. The plan consists of a nave, 62 feet by 26 feet; chancel, 24 feet by 17 feet; a small transept on the north side is to contain the organ, and the vestry is under the tower on the south side of the chancel. The tower is 65 feet high, surmounted by a metal cross, but at present only contains one bell. The whole of the roof timbers and doors are of oak ....."
[From The Chester Chronicle of 21 October 1867.]
The Clwyd FHS website has a photograph of the church.
St. Bartholomew's is a constituent church of the modern Rectorial Benefice of Hawarden - it is not a separate parish.
"Welsh Church Commission - County of Flint - The Statistics of the Nonconformist Churches for 1905" does not list any nonconformist places of worship for the Civil parish of Sealand.