My grandfather was John Glacken from Emmitsburg MD. I was told he was the illegitimate son of a James Glacken in Fredericks County Md. I too am seeking information on that branch. I was also told that we were related to William Glackens the famous Ashcan Painter from PA. John Glacken would have been born around 1878 and was a memeber of the Mount St Mary's Catholic Church where he marrid Margaret Elizabeth Peddicord. He was suppose to have relatives in Donegal Ireland.
At this time, that is all I have.
Let me know if you find anything that applies to me.