Scott, The 1857 dates were first proposed by Edgar Branch. More recent research by Michael Marleau indicates the year 1859 was the most likely dates of service on that boat in the company of Capt. William B. Miller. See this online article for the RUFUS J. LACKLAND. http://www.twainquotes.com/Steamboats/LicensedPilot.html Fears’s compilation was evidently based on Branch’s older research and not the updated research of Marleau. Barb