SPOILERS******SPOILERS******SPOILERS******SPOILERS*****SPOILERS
I seem to remember Hannah saying (in the musical) that Eli deserted the army, and when he came home, the shame of what he had done caused Hannah's husband to die of grief, which also finished off Eli emotionally (and caused him to take to the woods). Hannah knows he is there (she leaves him food) but even she can't bring herself to try to reach out to him until Percy forces the issue.
Also, didn't Percy miscarry because her stepfather beat her up late in the pregnancy, and that is why she can't have any more children (he also kidnapped her from the hospital before she recovered.)
I ask in all honesty/What would life be?/Without a song and a dance, what are we?/So I say "Thank you for the music/For giving it to me."