This video making the rounds on facebook claims that tipping in the US was started by the railroad and restaurant industries in the South after the Civil War so that they could hire freed slaves and either pay them very little or not pay them at all:
https://www.facebook.com/attn/videos/tipping/1623297677705685/
The video does not provide much in the way of sources other than a watermark for a UC Berkeley Labour Centre publication entitled "Why tipping is wrong". I would like to know if there is any veracity to this.
This earlier answer touches on this in a follow up which might be of interest to you.