The Appalachian Trail is a 2,180 mile trail along the ridge of the Appalachian mountains from Springer Mountain Georgia to Mount Katahdin, Maine

• History:
  The trail was conceived by forester, Benton MacKaye, in 1921. In 1923, the first section of the trail, from Bear Mountain west through Harriman State Park to Arden, New York, was opened. In 1937, the trail was completed to Sugarloaf Mountain in Maine.
  See wikipedia.
• Length: 2,181 in 2010. The distance and route changes from year to year.
  There are over 90 miles of elevation gain.
  See AT Elevation Gain and Loss - WhiteBlaze.net
  The section that runs just below the summit of Clingmans Dome in Great Smoky Mountains National Park is along the North Carolina and Tennessee border and is the highest point on the trail at 6,643 feet.
• Hikers: There are Day Hikers, Weekend Hikers, Section Hikers (They spend one or two weeks on the trail each year) and Thru hikers who do the whole thing in one year.
  Thru hikers tend to be individuals who have trail names and get to know each other as they share shelters and communicate with each other via the log books in each shelter.
  Most AT hikers are males between the ages of 18 and 29, but we met a man celebrating his 70th birthday on the trail and about 1/4 of the hikers were women. Famous thru hikers include Supreme Court Justice William O. Douglas.
• Thru Hikers:
  From 1,500-2,000 people start to thru hike each year (About 20 percent of hikers who begin the trail will complete it.). See number completing the AT by year.
• Average Time: 5 - 7 Months.
• Speed: Most hikers average 12 to 18 miles per day.
  A ultra-light (20 lb. pack) hiker I met on the train said she had done a 52 mile day in 15 hrs.
• The overall record up to 2011 was set by Andrew Thompson in 2005: 47 days 13 hours 31 minutes. (46 miles/day)
  In 2011 Jennifer Pharr Davis set the overall record of 46 days, 11 hours, besting Andrew Thompson record of 47 days in 2005. Pharr Davis previously set the women's record of 57 days in 2008. She hikes an 15-18 hrs./day 5 AM to 10 PM averaging almost 3 MPH.
  See Asheville woman sets Appalachian Trail record
  
• Cost: About $3,000
• Direction - Start Dates: The majority of thru-hikers hike northbound, beginning in Georgia anytime from late-March to mid-April.
• Shelters: Shelters (lean-to huts) are spaced about a day's hike apart, near water sources. There are usually tent sights around the shelters and a latrine (outhouse).
  Other accommodations: Most hikers take a day or two off every couple of weeks to get a shower and bed at a local hostel, guest house or motel and a good meal at a restaurant do laundry and re-supply. Some take a break for sightseeing at D.C., New York or other locations.
  See Appalachian Trail hostel accommodationsand location information page
• Food: Hikers can burn over 6,000 calories per day and loose weight. Food with high calorie and fat with light weight are preferred.
  Common dinner food: Instant rice, cous-cous, Knorr-type soup/bean mixes, ramen (cooked), ramen (instant), Stove Top Dressing, canned chicken, sardines, tuna, instant mashed potatoes, pasta, Lipton noodle or rice dinners.
  See Food at TrailQuest.net
• Supplies: The trail crosses a road an average of every four miles, making it pretty easy to access trail towns along the way.
  Many thru-hikers set up a series of maildrops, sending packages to themselves in predetermined towns along the route. These packages, on average, contain about a week's worth of food and supplies to last until the next town where one can resupply.
• Trail Angels: Local residents, called Trail Angels, frequently leave coolers with cold water, fruit, ... in coolers where the trail crosses a road.
• Ownership: The trail used to traverse many hundreds of miles of private property; currently 99% of the trail is on public land.
• Trail Maintenance: Most trail work is done by volunteers in 31 affiliated trail clubs. See Maintenance Of The Appalachian Trail at TrailQuest.net

Books, Guides, Maps:
Bryson, Bill, A Walk in the Woods: Rediscovering America on the Appalachian Trail.
Long, John, The Complete Hiker.
Larry Luxenberg, Walking the Appalachian Trail
Appalachian Trail Books that inspire and entertain at Amazon
The Appalachian Trail Conservancy
  Guides, Maps & Planning
  Mapping & GIS Data

Maps:
Map above from Abby's hiketheeast.wordpress.com page
The Appalachian Trail Conservancy's Interactive Map
Whole trail at Wikimedia.org
AppalachianTrail.com | Maps, Pictures, Hikers
Appalachian Trail Hiker and Volunteer Resources at the Appalachian Mountain Club
Appalachian National Scenic Trail (U.S. National Park Service)
Appalachian Trail Thru-Hike Planning
Appalachian Trail Planner
Appalachian Trail Home Page By Kathy Bilton, Shepherdstown
AT near Lynchburg - Roanoke, VA - Large map
AT in central VA reduced ver. from Fox on the Trail at rhodesmill.org/thefox/maps/
Delaware Water Gap -Appalachian Trail
Appalachian Trail Hiker and Volunteer Resources at the Appalachian Mountain Club

Links:
Sierra Club Introduction to Backpacking on the Appalachian Trail
The Appalachian Trail Conservancy
WhiteBlaze.net
AppalachianTrail.com | Maps, Pictures, Hikers
Trail Terms
Appalachian Trail Hiker and Volunteer Resources at the Appalachian Mountain Club
Appalachian National Scenic Trail (U.S. National Park Service)
Appalachian Trail Thru-Hike Planning
Appalachian Trail Planner
Appalachian Mountain Geology
Appalachian Trail Home Page By Kathy Bilton, Shepherdstown
Delaware Water Gap -Appalachian Trail
Sierra Club AT Backpack 2011

About Me:
I am a Sierra Club National Outings Leader who helped Zora run an Intro. to Backpacking Trip on the AT in 2011. I have hiked sections of the trail in 8 states, but am not a thru hiker.