My grandmother was a Catherine McNamara, born c 1875. She emigrated from Colmanstown, County Clare, to US in 1901. She joined her brother Thomas in Chicago. I don't think there is any connection to the group your looking for, but I can tell you that County Clare had numerous McNamara families. Check Griffith's Land Valuation, 1855, County Clare, you will find a wealth of McNamaras, the townland, and civil parish where the land was located. It's a free, on-line data base which may give you some clues to start with. Ellis Islan passenger lists is another, free data base to learn of any ancestors who arrived at the Port of New York between 1892 and 1924.