They were descendants of the Beregrim, kinsmen of the Dúnedain (especially those of the House of Beor) who did not leave Middle-earth at the end of the First Age. The Rivermen of Númeriador were actually Forodrim who had abandoned their old ways of life and had moved to the western borderlands of Arthedain.
In LOTRO there are a few mannish settlements in the North Downs including Esteldin, Trestlebridge, Stoneheight,small farmsteads as Gatson's Farm, Hodge's Farm and Peake's Farm, a Treasure Hunter's Camp at Deadmen's Dike and numerous campsites at Annúndir, Amon Raith, the Greenway, Amlaith's Scar, Mincham's Camp, Ost Crithlanc and in Evendim at Osforod, Barad Tharsír, Cirith Rhîw, Dol Haedír, Even-rills, Gloaming Falls, Haudh Arantar, Haudh Eldacar, Haudh Elendil, Haudh Eärendur, Ost-Heryn, Rantost, Tham Laegamon, Tham Ornen, Tham Sarch and Tham Varan.While the men of the North-downs are depicted as friendly most of the mannish inhabitants of evendim are shown as hostile brigands.
In the Lord of the Rings Books
In the Lord of the Rings Books it is stated that no men had settled dwellings so far west or within a hundred leagues of the Shire.This might either indicate that if there were still men living in these area, they may have been either nomads or at least that their settlements were small, thinly populated or instable in comparison to breeland and the shire.