Herbert
Hoover
was the second dead president, and the 24th overall, that my wife
Debbie and I visited on "The Five
DPOTUS Tour '05". Along with the dead presidents, we picked up
dead vice presidents, dead supreme court chief justices and losing
presidential candidates. We started out from Bayonne early in the
morning on Saturday, August 27. We drove through Pennsylvania and into
Ohio. We stopped in Fremont, Ohio to visit Rutherford B. Hayes. The
next day we continued, with numerous
stops, to Chicago. After spending the week in Chicago, we
headed on to Iowa to get Herbert Hoover and then back to Springfield,
Illinois. The next morning we visited Abraham Lincoln and then headed
off to Indianapolis, Indiana to see Benjamin Harrison, then on to
Dayton, Ohio for the night. The next
day, after stopping in Columbus, we headed north toward Marion, Ohio
and Warren G. Harding. 
Here are some webpages of interest:
White House Biography of Herbert Hoover
The Internet Public Library Biography
The American President Biography