Thanks, I had to fix to sed to escape the slashes correctly, but that was simple. It only seemed to correct one instance per line, but I just ran several times.
for file in $( find . -name "*.html" -print ); do sed -i.bak 's|\\|/|' $file; done
"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." - Benjamin Franklin, 1759 Historical Review of Pennsylvania