It is refreshing to find someone else researching the FEISEL surname. While I have no connection to Frederick T. Feisel that I am aware of at this point in time, I would like to offer the following observations from my research efforts to date. It appears that there are four distinct groups of Feisels in America: the Ohio/Michigan/Iowa group [my line]; a group in the Philadelphia area; a group in the Missouri/Illinois area; and the California group [your line].
The FEISEL surname is very rare in the U. S. as it is in Germany. It is felt that at some point in time those of us researching the FEISEL surname will find that common connection that we all seek.
As to my Feisel ancestors, I am only able to go back to about 1870. It is around that time that I assume my great-grandfather, Henry (or Heinrich) Feisel, arrived in the U. S. from Hesse-Darmstadt, Germany and located in Crawford County, Ohio. It is there that I find my grandfather, Henry Herman Feisel, being born in 1872. I have been unable to go back any further than that for all contact with my great-grandfather ceased when, in 1881, he deserted his wife and family. No trace of him has been found since that time.
As I say, I feel there is a common contact to be made somewhere out there and I welcome sharing information with anyone interested.