The Morwood branch of the tree is smaller (in terms of their presence in the US) and exclusively Irish. Although it is unknown when John Casey immigrated, Ann Skelley and newlywed William Morwood & Agnes Kelso immigrated in 1850. That is where the similarities end. William & Agnes were from Antrium County in Northern Ireland and likely Protestant. John and Ann were likely not from the northern counties and were Catholic.
Although the reason for their immigration is not listed, the timing came at the tail end of the Irish Potato Famine which suggests it is likely tied to that event. The subject families all immigrated to Baltimore, Maryland where they would have found support from the large Irish community that had already settled in the area.