What mush is this ?

[skylerKoba]

I found a lot of these mushrooms underneath some cedar trees in my backyard. It's late August almost early September, and I live in southeast Pennsylvania. 

The mushrooms are white, gilled, and have a bulbous bottom to them, plus a very distinct almost skirt around the middle of the stem. The top looks scaly, after looking into it it might be some sort of fly-attracting mushroom? There were a fair few flies around.

[vitog]

Check the spore print; if it's dark brown, it's probably be a species of Agaricus.  Some of these are edible, but others are poisonous; so, you need to verify the exact species before eating it.  The cap color reminds me of one of the poisonous ones, but I'm not familiar with eastern North American species.  You could consult mushroom expert.com for an identification key, but it would be best to get a positive ID from someone in your area.