Of all the things you could feed an elephant, why is there the cliche that they like peanuts? The only plausible guess I can think of is that back when zoos and circuses let you feed the animals, peanuts were a standard item for sale. Can anyone back this up?
Sheesh, why ask US if you already know?
http://www.aboutpeanuts.com/infohis.html
Elephants had long been featured in traveling shows that weren’t quite what we mean by “circuses”.
http://www.circusweb.com/cwhistory.html
The circus as we know it today really got underway in 1871.
http://www.cprr.org/Museum/This-way-to-the-Egress/
http://www.barnum-museum.org/html/jumbo.html
So, yeah, it looks like peanuts were becoming a mainstream snack at the same time that elephants were becoming a mainstream entertainment. What more logical than to hand an elephant one of your small, tidy snacks, and what more fascinating than to watch the way he delicately handled it with his trunk?
I thought that George Washington Carver discovered this use for the peanut along with 325 other uses. He was born in 1860, also.