In 1842, Bishop was sent to Croghan's estate (Locust Grove, in Louisville) for two weeks to draw a map, from memory, of the cave system (see Mammoth Cave). The map was published in 1844 by Morton and Griswold as a pull-out insert in Alexander Clark Bullitt's "Rambles in Mammoth Cave in the Year 1844 by a Visiter " (Morton and Griswold, 1845.) Unusually for an enslaved person, Bishop was given full credit for his work. The Bishop map remained in use for over forty years.