I need help ID'ing this button. I found it this weekend at a private residence and will be giving it to the owner. I just want to give them a little write-up to go along with the button. The eagle button is a Horstmann. I was able to ID a few letters on the back and make that conclusion. I can't make out any of the other letters on the back to narrow down the date. They really want to know if it is civil war era. What I know so far is that it is a general service button dating between 1820-1935. Thanks in advance for your help. I just haven't been able to narrow it down. I didn't find this particular button on the internet and my library doesn't have any good references.