I bought this cabinet card last year on a brief sojourn to the Gold Country. An antique store with no customers and one seller willing to sell things at half-price. So for two dollars I got this little fellow who travelled all the way from Pennsylvania to California.
Click on image to see it larger.
I wonder, if when his family saw this shot, they noticed his face was ever so slightly blurred. His feet are in focus, but his face isn't. I hadn't even noticed it until I enlarged it. It would have been such a disappointment to those who loved him. "Well John, at least your shoes were clean. Sigh." Let's hope Aunt Marie was pleasantly surprised when she received this from her nephew, John Conyer (?) Hays in 1896.
As to the photographer, A. E. Warren, I've found other photos online taken by him. An example here, with different more fanciful type, and here.
In 1894 Warren wrote a letter that was published in The Photographic Journal of America, Vol. 31 about the costs of doing business.
In 1898 he ran some ads in Meyer Brothers Druggist, Vol. 20 catalog.
Alas, also in 1898, tragedy befell Mr. Warren when his studio and home burned down. A brief piece was printed in Wilson's Photographic Magazine, Vol. 34, about the need for insurance.
Other than this I'm not finding anything about A. E. Warren. Nor have I found anything about young John Conyer Hays. At some point these two crossed paths and now they have crossed paths again 112 years later.