I think the one I quoted was in South Carolina, Turtle Old Man.

Just to get back to my original thought about it being another way to say "toe the line," this, found at Word Detective, seems to have some relation vis a vis starting lines and perhaps the navy reference leads to the cowboy use?:

Toe the line" first appeared in the early 18th century, and there are two possible "lines" to which the phrase might originally have referred. One would be the starting line of a foot race, the mark upon which each runner places his or her foot in preparation for the starting gun. The other possibility, which I find more likely, is a line drawn on a ship's deck or a parade ground which new recruits must "toe" as they assemble in formation. I find this source more persuasive because it echoes the connotations of "order" and "obedience" that "toe the line" retains today. It is to a runner's advantage, after all, to "toe" the starting line, but a recruit being ordered to "toe the line" is very quickly learning who is in charge.