I have found documentation that Joseph Imfeld arrived in Philadelphia aboard ship Phoenix, sailing from Rotterdam. I have found births to both Joseph and Vincent Imfeld in York, PA...but no John. I found no documentation in Frederick, MD of birth of John there, although that's info I was given as fact. Of interest (perhaps) to you is a Peter Impfield has court papers filed in Bedford Co., PA Sep 1850. He seems to be suing Wm Chenowith to collect a debt owed. Could there be a Peter IMPFIELD in your family tree???