"' When that they came to the middle of the course, Skewball and his rider began a discourse, Come, my brave rider, come tell unto me, How far is Miss Grizzle this moment from me.'

This is a Manchester (England) broadside (Bebbington, No. 206). In this version the mare with whom Skewball races is called 'Miss Grizzle."

That is from

http://www.traditionalmusic.co.uk/negro/folk-songs%20-%200162.htm