As the ridge runner, one of my jobs is to pack out gear left alongside the trail and in trail shelters. I am stationed at this time just 14 miles south of Katahdin. Thru hikers are realizing, apparently, they do no need a Bear Grills machete, an ax, a dozen stuff sacks, and heavy waterproof assortment of plastic containers (use zip lock baggies).
Also being abandoned, bars of soap (thankyou) bath salts, sling shot, cordage, dried beans, hats, and serious jack knives.
Clothing and even 8 packages of Ramen noodles, quarters and heavy metal rings, a 2014 data book, torn rainpants.
I post this list to help other hikers re-evaluate their packs, and for goodness sakes, don't let an outfitter sell you this stuff for a thru hike of the Appalachian Trail.
The first couple nights on a thru hike are the shake down. Hikers congregate, compare notes and bruises, pack weights and foods. Some plan to get through the 100 mile with out a resupply by local merchants offering such for fees. You can do this, embrace the challenge.
Give yourself 7 to 10 days of travel time. The serious hunger doesn't set in the first week. You'll be in Monson before you know it.
Just a few notes, from my side of the fence to save you some money and aggravation.