I am looking for any information on a Partland (or possibly McPartland) family that lived in Arganagh around 1800. I know only of John, born about 1802, who married Katherine Partland in 1827 in Boyle, Roscommon.

I suspect that they were cousins, but have no proof at all.

ANY information on John Partland and his family in County Sligo would be appreciated.

Interesting. We have a Eugene Partlan/Partland/McPartland (depending on the record) who married Anne Frazer and lived in Aghnasurn and Derreenargan, County Roscommon, right across the line from Aghanagh.
He had 2 children baptized in the church at Ballinafad, parish of Aghanagh, County Sligo, Catherine in 1860 and John in 1866.