I'm writing from Germany. My ancestors are also the Adickes (great-grandmother). She and already her ancestors have done a lot of research, which I have access to. In general, there are 3 Adickes families, seperated since around 1400. They marked their belonging by using one particular middle-name since then. For my family, this was "Johann" or in English "John". Therefore, I would not be surprised, if your grandfather was relative to emigrants of my family to the US. I have a 3-generation family tree of "Eggerich Johann Adickes" who went to the US in the 19th century and married "Sarah Moore". I would like to follow up on that. Maybe you are interested and can help me.