I am much obliged to everyone for sharing your knowledge. Anyone interested in colonial-era travel might find Paul A. W. Wallace’s essay about the travel network in 18th century Pennsylvania worthwhile; it is preliminary to a later book.

Kearny's Army of the West averaged about 20 miles a day on the trek from Fort Leavenworth to Bent's fort.
This figure might bear some scrutiny. Surely anyone given the opportunity to leave Fort Leavenworth behind them would do so at a faster clip.