The link to "Evidence for Ancestry of David Hartzell" has been changed to  

http://www.jdhartsell.com/DavidHartzell/evidence.html  

The link to "The Life of David Hartzell (1805-1865)" has been changed to  

http://www.jdhartsell.com/DavidHartzell/index.html  

For more on Adam Hartzell, see